diff --git a/homeassistant/components/climate/__init__.py b/homeassistant/components/climate/__init__.py
index cc26bcc9bcc..0b80402b3ec 100644
--- a/homeassistant/components/climate/__init__.py
+++ b/homeassistant/components/climate/__init__.py
@@ -18,6 +18,7 @@ from homeassistant.const import (
     STATE_OFF,
     STATE_ON,
     TEMP_CELSIUS,
+    UnitTemperatureT,
 )
 from homeassistant.core import HomeAssistant, ServiceCall
 import homeassistant.helpers.config_validation as cv
@@ -195,7 +196,7 @@ class ClimateEntity(Entity):
     _attr_target_temperature_low: float | None
     _attr_target_temperature_step: float | None = None
     _attr_target_temperature: float | None = None
-    _attr_temperature_unit: str
+    _attr_temperature_unit: UnitTemperatureT
 
     @property
     def state(self) -> str:
@@ -303,7 +304,7 @@ class ClimateEntity(Entity):
         return data
 
     @property
-    def temperature_unit(self) -> str:
+    def temperature_unit(self) -> UnitTemperatureT:
         """Return the unit of measurement used by the platform."""
         return self._attr_temperature_unit
 
diff --git a/homeassistant/components/climate/device_trigger.py b/homeassistant/components/climate/device_trigger.py
index 1b5127d7d4a..db8eeedd54c 100644
--- a/homeassistant/components/climate/device_trigger.py
+++ b/homeassistant/components/climate/device_trigger.py
@@ -19,6 +19,7 @@ from homeassistant.const import (
     CONF_PLATFORM,
     CONF_TYPE,
     PERCENTAGE,
+    UnitT,
 )
 from homeassistant.core import CALLBACK_TYPE, HomeAssistant
 from homeassistant.helpers import config_validation as cv, entity_registry
@@ -172,6 +173,7 @@ async def async_get_trigger_capabilities(hass: HomeAssistant, config):
             )
         }
 
+    unit_of_measurement: UnitT
     if trigger_type == "current_temperature_changed":
         unit_of_measurement = hass.config.units.temperature_unit
     else:
diff --git a/homeassistant/components/devolo_home_control/climate.py b/homeassistant/components/devolo_home_control/climate.py
index 6b890544da5..cad439eb284 100644
--- a/homeassistant/components/devolo_home_control/climate.py
+++ b/homeassistant/components/devolo_home_control/climate.py
@@ -11,7 +11,7 @@ from homeassistant.components.climate import (
     ClimateEntity,
 )
 from homeassistant.config_entries import ConfigEntry
-from homeassistant.const import PRECISION_HALVES, PRECISION_TENTHS
+from homeassistant.const import PRECISION_HALVES, PRECISION_TENTHS, UnitTemperatureT
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
 
@@ -105,7 +105,7 @@ class DevoloClimateDeviceEntity(DevoloMultiLevelSwitchDeviceEntity, ClimateEntit
         return SUPPORT_TARGET_TEMPERATURE
 
     @property
-    def temperature_unit(self) -> str:
+    def temperature_unit(self) -> UnitTemperatureT:
         """Return the supported unit of temperature."""
         return TEMP_CELSIUS
 
diff --git a/homeassistant/components/esphome/climate.py b/homeassistant/components/esphome/climate.py
index 218f0fb319b..016d197e8d9 100644
--- a/homeassistant/components/esphome/climate.py
+++ b/homeassistant/components/esphome/climate.py
@@ -65,6 +65,7 @@ from homeassistant.const import (
     PRECISION_TENTHS,
     PRECISION_WHOLE,
     TEMP_CELSIUS,
+    UnitTemperatureT,
 )
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
@@ -166,7 +167,7 @@ class EsphomeClimateEntity(EsphomeEntity[ClimateInfo, ClimateState], ClimateEnti
         return PRECISION_TENTHS
 
     @property
-    def temperature_unit(self) -> str:
+    def temperature_unit(self) -> UnitTemperatureT:
         """Return the unit of measurement used by the platform."""
         return TEMP_CELSIUS
 
diff --git a/homeassistant/components/fritzbox/climate.py b/homeassistant/components/fritzbox/climate.py
index c50e0d4f270..7f3ee76b48e 100644
--- a/homeassistant/components/fritzbox/climate.py
+++ b/homeassistant/components/fritzbox/climate.py
@@ -23,6 +23,7 @@ from homeassistant.const import (
     ATTR_UNIT_OF_MEASUREMENT,
     PRECISION_HALVES,
     TEMP_CELSIUS,
+    UnitTemperatureT,
 )
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
@@ -97,7 +98,7 @@ class FritzboxThermostat(FritzBoxEntity, ClimateEntity):
         return self.device.present  # type: ignore [no-any-return]
 
     @property
-    def temperature_unit(self) -> str:
+    def temperature_unit(self) -> UnitTemperatureT:
         """Return the unit of measurement that is used."""
         return TEMP_CELSIUS
 
diff --git a/homeassistant/components/lcn/climate.py b/homeassistant/components/lcn/climate.py
index 0a595076a8d..e453f26c25c 100644
--- a/homeassistant/components/lcn/climate.py
+++ b/homeassistant/components/lcn/climate.py
@@ -18,6 +18,9 @@ from homeassistant.const import (
     CONF_ENTITIES,
     CONF_SOURCE,
     CONF_UNIT_OF_MEASUREMENT,
+    TEMP_CELSIUS,
+    TEMP_FAHRENHEIT,
+    UnitTemperatureT,
 )
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
 from homeassistant.helpers.typing import ConfigType, HomeAssistantType
@@ -107,9 +110,12 @@ class LcnClimate(LcnEntity, ClimateEntity):
         return const.SUPPORT_TARGET_TEMPERATURE
 
     @property
-    def temperature_unit(self) -> str:
+    def temperature_unit(self) -> UnitTemperatureT:
         """Return the unit of measurement."""
-        return cast(str, self.unit.value)
+        # Config schema only allows for: TEMP_CELSIUS and TEMP_FAHRENHEIT
+        if self.unit == pypck.lcn_defs.VarUnit.FAHRENHEIT:
+            return TEMP_FAHRENHEIT
+        return TEMP_CELSIUS
 
     @property
     def current_temperature(self) -> float | None:
diff --git a/homeassistant/components/mysensors/climate.py b/homeassistant/components/mysensors/climate.py
index 5dd52673581..5afb4a803d2 100644
--- a/homeassistant/components/mysensors/climate.py
+++ b/homeassistant/components/mysensors/climate.py
@@ -19,7 +19,12 @@ from homeassistant.components.climate.const import (
 )
 from homeassistant.components.mysensors.const import MYSENSORS_DISCOVERY, DiscoveryInfo
 from homeassistant.config_entries import ConfigEntry
-from homeassistant.const import ATTR_TEMPERATURE, TEMP_CELSIUS, TEMP_FAHRENHEIT
+from homeassistant.const import (
+    ATTR_TEMPERATURE,
+    TEMP_CELSIUS,
+    TEMP_FAHRENHEIT,
+    UnitTemperatureT,
+)
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers.dispatcher import async_dispatcher_connect
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
@@ -91,7 +96,7 @@ class MySensorsHVAC(mysensors.device.MySensorsEntity, ClimateEntity):
         return features
 
     @property
-    def temperature_unit(self) -> str:
+    def temperature_unit(self) -> UnitTemperatureT:
         """Return the unit of measurement."""
         return TEMP_CELSIUS if self.hass.config.units.is_metric else TEMP_FAHRENHEIT
 
diff --git a/homeassistant/components/zwave_js/climate.py b/homeassistant/components/zwave_js/climate.py
index 1621e87cfab..62da8cc8c80 100644
--- a/homeassistant/components/zwave_js/climate.py
+++ b/homeassistant/components/zwave_js/climate.py
@@ -53,6 +53,7 @@ from homeassistant.const import (
     PRECISION_TENTHS,
     TEMP_CELSIUS,
     TEMP_FAHRENHEIT,
+    UnitTemperatureT,
 )
 from homeassistant.core import HomeAssistant, callback
 from homeassistant.helpers.dispatcher import async_dispatcher_connect
@@ -248,7 +249,7 @@ class ZWaveClimate(ZWaveBaseEntity, ClimateEntity):
         return THERMOSTAT_MODE_SETPOINT_MAP.get(int(self._current_mode.value), [])  # type: ignore
 
     @property
-    def temperature_unit(self) -> str:
+    def temperature_unit(self) -> UnitTemperatureT:
         """Return the unit of measurement used by the platform."""
         if (
             self._unit_value
diff --git a/homeassistant/const.py b/homeassistant/const.py
index 35b946fc6ab..3f07196d570 100644
--- a/homeassistant/const.py
+++ b/homeassistant/const.py
@@ -1,7 +1,7 @@
 """Constants used by Home Assistant components."""
 from __future__ import annotations
 
-from typing import Final
+from typing import Final, NewType
 
 MAJOR_VERSION: Final = 2021
 MINOR_VERSION: Final = 8
@@ -393,166 +393,212 @@ ATTR_DEVICE_CLASS: Final = "device_class"
 # Temperature attribute
 ATTR_TEMPERATURE: Final = "temperature"
 
+
 # #### UNITS OF MEASUREMENT ####
+UnitT = NewType("UnitT", str)
+
 # Power units
-POWER_WATT: Final = "W"
-POWER_KILO_WATT: Final = "kW"
+UnitPowerT = NewType("UnitPowerT", UnitT)
+POWER_WATT: Final[UnitPowerT] = UnitPowerT(UnitT("W"))
+POWER_KILO_WATT: Final[UnitPowerT] = UnitPowerT(UnitT("kW"))
 
 # Voltage units
-VOLT: Final = "V"
+VOLT: Final[UnitT] = UnitT("V")
 
 # Energy units
-ENERGY_WATT_HOUR: Final = "Wh"
-ENERGY_KILO_WATT_HOUR: Final = "kWh"
+UnitEnergyT = NewType("UnitEnergyT", UnitT)
+ENERGY_WATT_HOUR: Final[UnitEnergyT] = UnitEnergyT(UnitT("Wh"))
+ENERGY_KILO_WATT_HOUR: Final[UnitEnergyT] = UnitEnergyT(UnitT("kWh"))
 
 # Electrical units
-ELECTRICAL_CURRENT_AMPERE: Final = "A"
-ELECTRICAL_VOLT_AMPERE: Final = "VA"
+ELECTRICAL_CURRENT_AMPERE: Final[UnitT] = UnitT("A")
+ELECTRICAL_VOLT_AMPERE: Final[UnitT] = UnitT("VA")
 
 # Degree units
-DEGREE: Final = "°"
+DEGREE: Final[UnitT] = UnitT("°")
 
 # Currency units
-CURRENCY_EURO: Final = "€"
-CURRENCY_DOLLAR: Final = "$"
-CURRENCY_CENT: Final = "¢"
+UnitCurrencyT = NewType("UnitCurrencyT", UnitT)
+CURRENCY_EURO: Final[UnitCurrencyT] = UnitCurrencyT(UnitT("€"))
+CURRENCY_DOLLAR: Final[UnitCurrencyT] = UnitCurrencyT(UnitT("$"))
+CURRENCY_CENT: Final[UnitCurrencyT] = UnitCurrencyT(UnitT("¢"))
 
 # Temperature units
-TEMP_CELSIUS: Final = "°C"
-TEMP_FAHRENHEIT: Final = "°F"
-TEMP_KELVIN: Final = "K"
+UnitTemperatureT = NewType("UnitTemperatureT", UnitT)
+TEMP_CELSIUS: Final[UnitTemperatureT] = UnitTemperatureT(UnitT("°C"))
+TEMP_FAHRENHEIT: Final[UnitTemperatureT] = UnitTemperatureT(UnitT("°F"))
+TEMP_KELVIN: Final[UnitTemperatureT] = UnitTemperatureT(UnitT("K"))
 
 # Time units
-TIME_MICROSECONDS: Final = "μs"
-TIME_MILLISECONDS: Final = "ms"
-TIME_SECONDS: Final = "s"
-TIME_MINUTES: Final = "min"
-TIME_HOURS: Final = "h"
-TIME_DAYS: Final = "d"
-TIME_WEEKS: Final = "w"
-TIME_MONTHS: Final = "m"
-TIME_YEARS: Final = "y"
+UnitTimeT = NewType("UnitTimeT", UnitT)
+TIME_MICROSECONDS: Final[UnitTimeT] = UnitTimeT(UnitT("μs"))
+TIME_MILLISECONDS: Final[UnitTimeT] = UnitTimeT(UnitT("ms"))
+TIME_SECONDS: Final[UnitTimeT] = UnitTimeT(UnitT("s"))
+TIME_MINUTES: Final[UnitTimeT] = UnitTimeT(UnitT("min"))
+TIME_HOURS: Final[UnitTimeT] = UnitTimeT(UnitT("h"))
+TIME_DAYS: Final[UnitTimeT] = UnitTimeT(UnitT("d"))
+TIME_WEEKS: Final[UnitTimeT] = UnitTimeT(UnitT("w"))
+TIME_MONTHS: Final[UnitTimeT] = UnitTimeT(UnitT("m"))
+TIME_YEARS: Final[UnitTimeT] = UnitTimeT(UnitT("y"))
 
 # Length units
-LENGTH_MILLIMETERS: Final = "mm"
-LENGTH_CENTIMETERS: Final = "cm"
-LENGTH_METERS: Final = "m"
-LENGTH_KILOMETERS: Final = "km"
+UnitLengthT = NewType("UnitLengthT", UnitT)
+LENGTH_MILLIMETERS: Final[UnitLengthT] = UnitLengthT(UnitT("mm"))
+LENGTH_CENTIMETERS: Final[UnitLengthT] = UnitLengthT(UnitT("cm"))
+LENGTH_METERS: Final[UnitLengthT] = UnitLengthT(UnitT("m"))
+LENGTH_KILOMETERS: Final[UnitLengthT] = UnitLengthT(UnitT("km"))
 
-LENGTH_INCHES: Final = "in"
-LENGTH_FEET: Final = "ft"
-LENGTH_YARD: Final = "yd"
-LENGTH_MILES: Final = "mi"
+LENGTH_INCHES: Final[UnitLengthT] = UnitLengthT(UnitT("in"))
+LENGTH_FEET: Final[UnitLengthT] = UnitLengthT(UnitT("ft"))
+LENGTH_YARD: Final[UnitLengthT] = UnitLengthT(UnitT("yd"))
+LENGTH_MILES: Final[UnitLengthT] = UnitLengthT(UnitT("mi"))
 
 # Frequency units
-FREQUENCY_HERTZ: Final = "Hz"
-FREQUENCY_GIGAHERTZ: Final = "GHz"
+UnitFrequencyT = NewType("UnitFrequencyT", UnitT)
+FREQUENCY_HERTZ: Final[UnitFrequencyT] = UnitFrequencyT(UnitT("Hz"))
+FREQUENCY_GIGAHERTZ: Final[UnitFrequencyT] = UnitFrequencyT(UnitT("GHz"))
 
 # Pressure units
-PRESSURE_PA: Final = "Pa"
-PRESSURE_HPA: Final = "hPa"
-PRESSURE_BAR: Final = "bar"
-PRESSURE_MBAR: Final = "mbar"
-PRESSURE_INHG: Final = "inHg"
-PRESSURE_PSI: Final = "psi"
+UnitPressureT = NewType("UnitPressureT", UnitT)
+PRESSURE_PA: Final[UnitPressureT] = UnitPressureT(UnitT("Pa"))
+PRESSURE_HPA: Final[UnitPressureT] = UnitPressureT(UnitT("hPa"))
+PRESSURE_BAR: Final[UnitPressureT] = UnitPressureT(UnitT("bar"))
+PRESSURE_MBAR: Final[UnitPressureT] = UnitPressureT(UnitT("mbar"))
+PRESSURE_INHG: Final[UnitPressureT] = UnitPressureT(UnitT("inHg"))
+PRESSURE_PSI: Final[UnitPressureT] = UnitPressureT(UnitT("psi"))
 
 # Volume units
-VOLUME_LITERS: Final = "L"
-VOLUME_MILLILITERS: Final = "mL"
-VOLUME_CUBIC_METERS: Final = "m³"
-VOLUME_CUBIC_FEET: Final = "ft³"
+UnitVolumeT = NewType("UnitVolumeT", UnitT)
+VOLUME_LITERS: Final[UnitVolumeT] = UnitVolumeT(UnitT("L"))
+VOLUME_MILLILITERS: Final[UnitVolumeT] = UnitVolumeT(UnitT("mL"))
+VOLUME_CUBIC_METERS: Final[UnitVolumeT] = UnitVolumeT(UnitT("m³"))
+VOLUME_CUBIC_FEET: Final[UnitVolumeT] = UnitVolumeT(UnitT("ft³"))
 
-VOLUME_GALLONS: Final = "gal"
-VOLUME_FLUID_OUNCE: Final = "fl. oz."
+VOLUME_GALLONS: Final[UnitVolumeT] = UnitVolumeT(UnitT("gal"))
+VOLUME_FLUID_OUNCE: Final[UnitVolumeT] = UnitVolumeT(UnitT("fl. oz."))
 
 # Volume Flow Rate units
-VOLUME_FLOW_RATE_CUBIC_METERS_PER_HOUR: Final = "m³/h"
-VOLUME_FLOW_RATE_CUBIC_FEET_PER_MINUTE: Final = "ft³/m"
+UnitVolumeFlowT = NewType("UnitVolumeFlowT", UnitT)
+VOLUME_FLOW_RATE_CUBIC_METERS_PER_HOUR: Final[UnitVolumeFlowT] = UnitVolumeFlowT(
+    UnitT("m³/h")
+)
+VOLUME_FLOW_RATE_CUBIC_FEET_PER_MINUTE: Final[UnitVolumeFlowT] = UnitVolumeFlowT(
+    UnitT("ft³/m")
+)
 
 # Area units
-AREA_SQUARE_METERS: Final = "m²"
+UnitAreaT = NewType("UnitAreaT", UnitT)
+AREA_SQUARE_METERS: Final[UnitAreaT] = UnitAreaT(UnitT("m²"))
 
 # Mass units
-MASS_GRAMS: Final = "g"
-MASS_KILOGRAMS: Final = "kg"
-MASS_MILLIGRAMS: Final = "mg"
-MASS_MICROGRAMS: Final = "µg"
+UnitMassT = NewType("UnitMassT", UnitT)
+MASS_GRAMS: Final[UnitMassT] = UnitMassT(UnitT("g"))
+MASS_KILOGRAMS: Final[UnitMassT] = UnitMassT(UnitT("kg"))
+MASS_MILLIGRAMS: Final[UnitMassT] = UnitMassT(UnitT("mg"))
+MASS_MICROGRAMS: Final[UnitMassT] = UnitMassT(UnitT("µg"))
 
-MASS_OUNCES: Final = "oz"
-MASS_POUNDS: Final = "lb"
+MASS_OUNCES: Final[UnitMassT] = UnitMassT(UnitT("oz"))
+MASS_POUNDS: Final[UnitMassT] = UnitMassT(UnitT("lb"))
 
 # Conductivity units
-CONDUCTIVITY: Final = "µS/cm"
+CONDUCTIVITY: Final[UnitT] = UnitT("µS/cm")
 
 # Light units
-LIGHT_LUX: Final = "lx"
+LIGHT_LUX: Final[UnitT] = UnitT("lx")
 
 # UV Index units
-UV_INDEX: Final = "UV index"
+UV_INDEX: Final[UnitT] = UnitT("UV index")
 
 # Percentage units
-PERCENTAGE: Final = "%"
+PERCENTAGE: Final[UnitT] = UnitT("%")
 
 # Irradiation units
-IRRADIATION_WATTS_PER_SQUARE_METER: Final = "W/m²"
-IRRADIATION_BTUS_PER_HOUR_SQUARE_FOOT: Final = "BTU/(h×ft²)"
+UnitIrradiationT = NewType("UnitIrradiationT", UnitT)
+IRRADIATION_WATTS_PER_SQUARE_METER: Final[UnitIrradiationT] = UnitIrradiationT(
+    UnitT("W/m²")
+)
+IRRADIATION_BTUS_PER_HOUR_SQUARE_FOOT: Final[UnitIrradiationT] = UnitIrradiationT(
+    UnitT("BTU/(h×ft²)")
+)
 
 # Precipitation units
-PRECIPITATION_MILLIMETERS_PER_HOUR: Final = "mm/h"
+PRECIPITATION_MILLIMETERS_PER_HOUR: Final[UnitT] = UnitT("mm/h")
 
 # Concentration units
-CONCENTRATION_MICROGRAMS_PER_CUBIC_METER: Final = "µg/m³"
-CONCENTRATION_MILLIGRAMS_PER_CUBIC_METER: Final = "mg/m³"
-CONCENTRATION_MICROGRAMS_PER_CUBIC_FOOT: Final = "μg/ft³"
-CONCENTRATION_PARTS_PER_CUBIC_METER: Final = "p/m³"
-CONCENTRATION_PARTS_PER_MILLION: Final = "ppm"
-CONCENTRATION_PARTS_PER_BILLION: Final = "ppb"
+UnitConcentrationT = NewType("UnitConcentrationT", UnitT)
+CONCENTRATION_MICROGRAMS_PER_CUBIC_METER: Final[
+    UnitConcentrationT
+] = UnitConcentrationT(UnitT("µg/m³"))
+CONCENTRATION_MILLIGRAMS_PER_CUBIC_METER: Final[
+    UnitConcentrationT
+] = UnitConcentrationT(UnitT("mg/m³"))
+CONCENTRATION_MICROGRAMS_PER_CUBIC_FOOT: Final[UnitConcentrationT] = UnitConcentrationT(
+    UnitT("μg/ft³")
+)
+CONCENTRATION_PARTS_PER_CUBIC_METER: Final[UnitConcentrationT] = UnitConcentrationT(
+    UnitT("p/m³")
+)
+CONCENTRATION_PARTS_PER_MILLION: Final[UnitConcentrationT] = UnitConcentrationT(
+    UnitT("ppm")
+)
+CONCENTRATION_PARTS_PER_BILLION: Final[UnitConcentrationT] = UnitConcentrationT(
+    UnitT("ppb")
+)
 
 # Speed units
-SPEED_MILLIMETERS_PER_DAY: Final = "mm/d"
-SPEED_INCHES_PER_DAY: Final = "in/d"
-SPEED_METERS_PER_SECOND: Final = "m/s"
-SPEED_INCHES_PER_HOUR: Final = "in/h"
-SPEED_KILOMETERS_PER_HOUR: Final = "km/h"
-SPEED_MILES_PER_HOUR: Final = "mph"
+UnitSpeedT = NewType("UnitSpeedT", UnitT)
+SPEED_MILLIMETERS_PER_DAY: Final[UnitSpeedT] = UnitSpeedT(UnitT("mm/d"))
+SPEED_INCHES_PER_DAY: Final[UnitSpeedT] = UnitSpeedT(UnitT("in/d"))
+SPEED_METERS_PER_SECOND: Final[UnitSpeedT] = UnitSpeedT(UnitT("m/s"))
+SPEED_INCHES_PER_HOUR: Final[UnitSpeedT] = UnitSpeedT(UnitT("in/h"))
+SPEED_KILOMETERS_PER_HOUR: Final[UnitSpeedT] = UnitSpeedT(UnitT("km/h"))
+SPEED_MILES_PER_HOUR: Final[UnitSpeedT] = UnitSpeedT(UnitT("mph"))
 
 # Signal_strength units
-SIGNAL_STRENGTH_DECIBELS: Final = "dB"
-SIGNAL_STRENGTH_DECIBELS_MILLIWATT: Final = "dBm"
+UnitSignalStrengthT = NewType("UnitSignalStrengthT", UnitT)
+SIGNAL_STRENGTH_DECIBELS: Final[UnitSignalStrengthT] = UnitSignalStrengthT(UnitT("dB"))
+SIGNAL_STRENGTH_DECIBELS_MILLIWATT: Final[UnitSignalStrengthT] = UnitSignalStrengthT(
+    UnitT("dBm")
+)
 
 # Data units
-DATA_BITS: Final = "bit"
-DATA_KILOBITS: Final = "kbit"
-DATA_MEGABITS: Final = "Mbit"
-DATA_GIGABITS: Final = "Gbit"
-DATA_BYTES: Final = "B"
-DATA_KILOBYTES: Final = "kB"
-DATA_MEGABYTES: Final = "MB"
-DATA_GIGABYTES: Final = "GB"
-DATA_TERABYTES: Final = "TB"
-DATA_PETABYTES: Final = "PB"
-DATA_EXABYTES: Final = "EB"
-DATA_ZETTABYTES: Final = "ZB"
-DATA_YOTTABYTES: Final = "YB"
-DATA_KIBIBYTES: Final = "KiB"
-DATA_MEBIBYTES: Final = "MiB"
-DATA_GIBIBYTES: Final = "GiB"
-DATA_TEBIBYTES: Final = "TiB"
-DATA_PEBIBYTES: Final = "PiB"
-DATA_EXBIBYTES: Final = "EiB"
-DATA_ZEBIBYTES: Final = "ZiB"
-DATA_YOBIBYTES: Final = "YiB"
-DATA_RATE_BITS_PER_SECOND: Final = "bit/s"
-DATA_RATE_KILOBITS_PER_SECOND: Final = "kbit/s"
-DATA_RATE_MEGABITS_PER_SECOND: Final = "Mbit/s"
-DATA_RATE_GIGABITS_PER_SECOND: Final = "Gbit/s"
-DATA_RATE_BYTES_PER_SECOND: Final = "B/s"
-DATA_RATE_KILOBYTES_PER_SECOND: Final = "kB/s"
-DATA_RATE_MEGABYTES_PER_SECOND: Final = "MB/s"
-DATA_RATE_GIGABYTES_PER_SECOND: Final = "GB/s"
-DATA_RATE_KIBIBYTES_PER_SECOND: Final = "KiB/s"
-DATA_RATE_MEBIBYTES_PER_SECOND: Final = "MiB/s"
-DATA_RATE_GIBIBYTES_PER_SECOND: Final = "GiB/s"
+UnitDataT = NewType("UnitDataT", UnitT)
+DATA_BITS: Final[UnitDataT] = UnitDataT(UnitT("bit"))
+DATA_KILOBITS: Final[UnitDataT] = UnitDataT(UnitT("kbit"))
+DATA_MEGABITS: Final[UnitDataT] = UnitDataT(UnitT("Mbit"))
+DATA_GIGABITS: Final[UnitDataT] = UnitDataT(UnitT("Gbit"))
+DATA_BYTES: Final[UnitDataT] = UnitDataT(UnitT("B"))
+DATA_KILOBYTES: Final[UnitDataT] = UnitDataT(UnitT("kB"))
+DATA_MEGABYTES: Final[UnitDataT] = UnitDataT(UnitT("MB"))
+DATA_GIGABYTES: Final[UnitDataT] = UnitDataT(UnitT("GB"))
+DATA_TERABYTES: Final[UnitDataT] = UnitDataT(UnitT("TB"))
+DATA_PETABYTES: Final[UnitDataT] = UnitDataT(UnitT("PB"))
+DATA_EXABYTES: Final[UnitDataT] = UnitDataT(UnitT("EB"))
+DATA_ZETTABYTES: Final[UnitDataT] = UnitDataT(UnitT("ZB"))
+DATA_YOTTABYTES: Final[UnitDataT] = UnitDataT(UnitT("YB"))
+DATA_KIBIBYTES: Final[UnitDataT] = UnitDataT(UnitT("KiB"))
+DATA_MEBIBYTES: Final[UnitDataT] = UnitDataT(UnitT("MiB"))
+DATA_GIBIBYTES: Final[UnitDataT] = UnitDataT(UnitT("GiB"))
+DATA_TEBIBYTES: Final[UnitDataT] = UnitDataT(UnitT("TiB"))
+DATA_PEBIBYTES: Final[UnitDataT] = UnitDataT(UnitT("PiB"))
+DATA_EXBIBYTES: Final[UnitDataT] = UnitDataT(UnitT("EiB"))
+DATA_ZEBIBYTES: Final[UnitDataT] = UnitDataT(UnitT("ZiB"))
+DATA_YOBIBYTES: Final[UnitDataT] = UnitDataT(UnitT("YiB"))
+
+# Data_rate units
+UnitDataRateT = NewType("UnitDataRateT", UnitT)
+DATA_RATE_BITS_PER_SECOND: Final[UnitDataRateT] = UnitDataRateT(UnitT("bit/s"))
+DATA_RATE_KILOBITS_PER_SECOND: Final[UnitDataRateT] = UnitDataRateT(UnitT("kbit/s"))
+DATA_RATE_MEGABITS_PER_SECOND: Final[UnitDataRateT] = UnitDataRateT(UnitT("Mbit/s"))
+DATA_RATE_GIGABITS_PER_SECOND: Final[UnitDataRateT] = UnitDataRateT(UnitT("Gbit/s"))
+DATA_RATE_BYTES_PER_SECOND: Final[UnitDataRateT] = UnitDataRateT(UnitT("B/s"))
+DATA_RATE_KILOBYTES_PER_SECOND: Final[UnitDataRateT] = UnitDataRateT(UnitT("kB/s"))
+DATA_RATE_MEGABYTES_PER_SECOND: Final[UnitDataRateT] = UnitDataRateT(UnitT("MB/s"))
+DATA_RATE_GIGABYTES_PER_SECOND: Final[UnitDataRateT] = UnitDataRateT(UnitT("GB/s"))
+DATA_RATE_KIBIBYTES_PER_SECOND: Final[UnitDataRateT] = UnitDataRateT(UnitT("KiB/s"))
+DATA_RATE_MEBIBYTES_PER_SECOND: Final[UnitDataRateT] = UnitDataRateT(UnitT("MiB/s"))
+DATA_RATE_GIBIBYTES_PER_SECOND: Final[UnitDataRateT] = UnitDataRateT(UnitT("GiB/s"))
+
 
 # #### SERVICES ####
 SERVICE_HOMEASSISTANT_STOP: Final = "stop"
@@ -653,13 +699,14 @@ RESTART_EXIT_CODE: Final = 100
 
 UNIT_NOT_RECOGNIZED_TEMPLATE: Final = "{} is not a recognized {} unit."
 
-LENGTH: Final = "length"
-MASS: Final = "mass"
-PRESSURE: Final = "pressure"
-VOLUME: Final = "volume"
-TEMPERATURE: Final = "temperature"
-SPEED_MS: Final = "speed_ms"
-ILLUMINANCE: Final = "illuminance"
+UnitTypeT = NewType("UnitTypeT", str)
+LENGTH: Final[UnitTypeT] = UnitTypeT("length")
+MASS: Final[UnitTypeT] = UnitTypeT("mass")
+PRESSURE: Final[UnitTypeT] = UnitTypeT("pressure")
+VOLUME: Final[UnitTypeT] = UnitTypeT("volume")
+TEMPERATURE: Final[UnitTypeT] = UnitTypeT("temperature")
+SPEED_MS: Final[UnitTypeT] = UnitTypeT("speed_ms")
+ILLUMINANCE: Final[UnitTypeT] = UnitTypeT("illuminance")
 
 WEEKDAYS: Final[list[str]] = ["mon", "tue", "wed", "thu", "fri", "sat", "sun"]
 
diff --git a/homeassistant/helpers/temperature.py b/homeassistant/helpers/temperature.py
index e0f089e93b9..2693fc13fc2 100644
--- a/homeassistant/helpers/temperature.py
+++ b/homeassistant/helpers/temperature.py
@@ -3,13 +3,16 @@ from __future__ import annotations
 
 from numbers import Number
 
-from homeassistant.const import PRECISION_HALVES, PRECISION_TENTHS
+from homeassistant.const import PRECISION_HALVES, PRECISION_TENTHS, UnitTemperatureT
 from homeassistant.core import HomeAssistant
 from homeassistant.util.temperature import convert as convert_temperature
 
 
 def display_temp(
-    hass: HomeAssistant, temperature: float | None, unit: str, precision: float
+    hass: HomeAssistant,
+    temperature: float | None,
+    unit: UnitTemperatureT,
+    precision: float,
 ) -> float | None:
     """Convert temperature into preferred units/precision for display."""
     temperature_unit = unit
diff --git a/homeassistant/util/distance.py b/homeassistant/util/distance.py
index 592c7c3145e..921e2941760 100644
--- a/homeassistant/util/distance.py
+++ b/homeassistant/util/distance.py
@@ -15,9 +15,10 @@ from homeassistant.const import (
     LENGTH_MILLIMETERS,
     LENGTH_YARD,
     UNIT_NOT_RECOGNIZED_TEMPLATE,
+    UnitLengthT,
 )
 
-VALID_UNITS = [
+VALID_UNITS: tuple[UnitLengthT, ...] = (
     LENGTH_KILOMETERS,
     LENGTH_MILES,
     LENGTH_FEET,
@@ -26,9 +27,9 @@ VALID_UNITS = [
     LENGTH_MILLIMETERS,
     LENGTH_INCHES,
     LENGTH_YARD,
-]
+)
 
-TO_METERS: dict[str, Callable[[float], float]] = {
+TO_METERS: dict[UnitLengthT, Callable[[float], float]] = {
     LENGTH_METERS: lambda meters: meters,
     LENGTH_MILES: lambda miles: miles * 1609.344,
     LENGTH_YARD: lambda yards: yards * 0.9144,
@@ -39,7 +40,7 @@ TO_METERS: dict[str, Callable[[float], float]] = {
     LENGTH_MILLIMETERS: lambda millimeters: millimeters * 0.001,
 }
 
-METERS_TO: dict[str, Callable[[float], float]] = {
+METERS_TO: dict[UnitLengthT, Callable[[float], float]] = {
     LENGTH_METERS: lambda meters: meters,
     LENGTH_MILES: lambda meters: meters * 0.000621371,
     LENGTH_YARD: lambda meters: meters * 1.09361,
@@ -51,7 +52,7 @@ METERS_TO: dict[str, Callable[[float], float]] = {
 }
 
 
-def convert(value: float, unit_1: str, unit_2: str) -> float:
+def convert(value: float, unit_1: UnitLengthT, unit_2: UnitLengthT) -> float:
     """Convert one unit of measurement to another."""
     if unit_1 not in VALID_UNITS:
         raise ValueError(UNIT_NOT_RECOGNIZED_TEMPLATE.format(unit_1, LENGTH))
diff --git a/homeassistant/util/pressure.py b/homeassistant/util/pressure.py
index 24ad3242921..9939b02e141 100644
--- a/homeassistant/util/pressure.py
+++ b/homeassistant/util/pressure.py
@@ -1,4 +1,6 @@
 """Pressure util functions."""
+from __future__ import annotations
+
 from numbers import Number
 
 from homeassistant.const import (
@@ -9,11 +11,18 @@ from homeassistant.const import (
     PRESSURE_PA,
     PRESSURE_PSI,
     UNIT_NOT_RECOGNIZED_TEMPLATE,
+    UnitPressureT,
 )
 
-VALID_UNITS = [PRESSURE_PA, PRESSURE_HPA, PRESSURE_MBAR, PRESSURE_INHG, PRESSURE_PSI]
+VALID_UNITS: tuple[UnitPressureT, ...] = (
+    PRESSURE_PA,
+    PRESSURE_HPA,
+    PRESSURE_MBAR,
+    PRESSURE_INHG,
+    PRESSURE_PSI,
+)
 
-UNIT_CONVERSION = {
+UNIT_CONVERSION: dict[UnitPressureT, float] = {
     PRESSURE_PA: 1,
     PRESSURE_HPA: 1 / 100,
     PRESSURE_MBAR: 1 / 100,
@@ -22,7 +31,7 @@ UNIT_CONVERSION = {
 }
 
 
-def convert(value: float, unit_1: str, unit_2: str) -> float:
+def convert(value: float, unit_1: UnitPressureT, unit_2: UnitPressureT) -> float:
     """Convert one unit of measurement to another."""
     if unit_1 not in VALID_UNITS:
         raise ValueError(UNIT_NOT_RECOGNIZED_TEMPLATE.format(unit_1, PRESSURE))
diff --git a/homeassistant/util/temperature.py b/homeassistant/util/temperature.py
index bc3cb4c1017..015f33383d1 100644
--- a/homeassistant/util/temperature.py
+++ b/homeassistant/util/temperature.py
@@ -5,6 +5,7 @@ from homeassistant.const import (
     TEMP_KELVIN,
     TEMPERATURE,
     UNIT_NOT_RECOGNIZED_TEMPLATE,
+    UnitTemperatureT,
 )
 
 
@@ -37,7 +38,10 @@ def celsius_to_kelvin(celsius: float, interval: bool = False) -> float:
 
 
 def convert(
-    temperature: float, from_unit: str, to_unit: str, interval: bool = False
+    temperature: float,
+    from_unit: UnitTemperatureT,
+    to_unit: UnitTemperatureT,
+    interval: bool = False,
 ) -> float:
     """Convert a temperature from one unit to another."""
     if from_unit not in (TEMP_CELSIUS, TEMP_FAHRENHEIT, TEMP_KELVIN):
diff --git a/homeassistant/util/unit_system.py b/homeassistant/util/unit_system.py
index b5c8c38425a..e49c1895180 100644
--- a/homeassistant/util/unit_system.py
+++ b/homeassistant/util/unit_system.py
@@ -24,6 +24,13 @@ from homeassistant.const import (
     VOLUME,
     VOLUME_GALLONS,
     VOLUME_LITERS,
+    UnitLengthT,
+    UnitMassT,
+    UnitPressureT,
+    UnitT,
+    UnitTemperatureT,
+    UnitTypeT,
+    UnitVolumeT,
 )
 from homeassistant.util import (
     distance as distance_util,
@@ -36,17 +43,23 @@ from homeassistant.util import (
 
 LENGTH_UNITS = distance_util.VALID_UNITS
 
-MASS_UNITS = [MASS_POUNDS, MASS_OUNCES, MASS_KILOGRAMS, MASS_GRAMS]
+MASS_UNITS: tuple[UnitMassT, ...] = (
+    MASS_POUNDS,
+    MASS_OUNCES,
+    MASS_KILOGRAMS,
+    MASS_GRAMS,
+)
 
 PRESSURE_UNITS = pressure_util.VALID_UNITS
 
 VOLUME_UNITS = volume_util.VALID_UNITS
 
-TEMPERATURE_UNITS = [TEMP_FAHRENHEIT, TEMP_CELSIUS]
+TEMPERATURE_UNITS: tuple[UnitTemperatureT, ...] = (TEMP_FAHRENHEIT, TEMP_CELSIUS)
 
 
-def is_valid_unit(unit: str, unit_type: str) -> bool:
+def is_valid_unit(unit: UnitT, unit_type: UnitTypeT) -> bool:
     """Check if the unit is valid for it's type."""
+    units: tuple[UnitT, ...]
     if unit_type == LENGTH:
         units = LENGTH_UNITS
     elif unit_type == TEMPERATURE:
@@ -69,11 +82,11 @@ class UnitSystem:
     def __init__(
         self,
         name: str,
-        temperature: str,
-        length: str,
-        volume: str,
-        mass: str,
-        pressure: str,
+        temperature: UnitTemperatureT,
+        length: UnitLengthT,
+        volume: UnitVolumeT,
+        mass: UnitMassT,
+        pressure: UnitPressureT,
     ) -> None:
         """Initialize the unit system object."""
         errors: str = ", ".join(
@@ -103,14 +116,14 @@ class UnitSystem:
         """Determine if this is the metric unit system."""
         return self.name == CONF_UNIT_SYSTEM_METRIC
 
-    def temperature(self, temperature: float, from_unit: str) -> float:
+    def temperature(self, temperature: float, from_unit: UnitTemperatureT) -> float:
         """Convert the given temperature to this unit system."""
         if not isinstance(temperature, Number):
             raise TypeError(f"{temperature!s} is not a numeric value.")
 
         return temperature_util.convert(temperature, from_unit, self.temperature_unit)
 
-    def length(self, length: float | None, from_unit: str) -> float:
+    def length(self, length: float | None, from_unit: UnitLengthT) -> float:
         """Convert the given length to this unit system."""
         if not isinstance(length, Number):
             raise TypeError(f"{length!s} is not a numeric value.")
@@ -120,7 +133,7 @@ class UnitSystem:
             length, from_unit, self.length_unit
         )
 
-    def pressure(self, pressure: float | None, from_unit: str) -> float:
+    def pressure(self, pressure: float | None, from_unit: UnitPressureT) -> float:
         """Convert the given pressure to this unit system."""
         if not isinstance(pressure, Number):
             raise TypeError(f"{pressure!s} is not a numeric value.")
@@ -130,7 +143,7 @@ class UnitSystem:
             pressure, from_unit, self.pressure_unit
         )
 
-    def volume(self, volume: float | None, from_unit: str) -> float:
+    def volume(self, volume: float | None, from_unit: UnitVolumeT) -> float:
         """Convert the given volume to this unit system."""
         if not isinstance(volume, Number):
             raise TypeError(f"{volume!s} is not a numeric value.")
@@ -138,7 +151,7 @@ class UnitSystem:
         # type ignore: https://github.com/python/mypy/issues/7207
         return volume_util.convert(volume, from_unit, self.volume_unit)  # type: ignore
 
-    def as_dict(self) -> dict[str, str]:
+    def as_dict(self) -> dict[str, UnitT]:
         """Convert the unit system to a dictionary."""
         return {
             LENGTH: self.length_unit,
diff --git a/homeassistant/util/volume.py b/homeassistant/util/volume.py
index 5d94f848cd8..ddf2be5a3bc 100644
--- a/homeassistant/util/volume.py
+++ b/homeassistant/util/volume.py
@@ -1,4 +1,6 @@
 """Volume conversion util functions."""
+from __future__ import annotations
+
 from numbers import Number
 
 from homeassistant.const import (
@@ -8,9 +10,15 @@ from homeassistant.const import (
     VOLUME_GALLONS,
     VOLUME_LITERS,
     VOLUME_MILLILITERS,
+    UnitVolumeT,
 )
 
-VALID_UNITS = [VOLUME_LITERS, VOLUME_MILLILITERS, VOLUME_GALLONS, VOLUME_FLUID_OUNCE]
+VALID_UNITS: tuple[UnitVolumeT, ...] = (
+    VOLUME_LITERS,
+    VOLUME_MILLILITERS,
+    VOLUME_GALLONS,
+    VOLUME_FLUID_OUNCE,
+)
 
 
 def __liter_to_gallon(liter: float) -> float:
@@ -23,7 +31,7 @@ def __gallon_to_liter(gallon: float) -> float:
     return gallon * 3.785
 
 
-def convert(volume: float, from_unit: str, to_unit: str) -> float:
+def convert(volume: float, from_unit: UnitVolumeT, to_unit: UnitVolumeT) -> float:
     """Convert a temperature from one unit to another."""
     if from_unit not in VALID_UNITS:
         raise ValueError(UNIT_NOT_RECOGNIZED_TEMPLATE.format(from_unit, VOLUME))