diff --git a/homeassistant/components/airnow/const.py b/homeassistant/components/airnow/const.py
index 054a5cbfea7..1198f68128d 100644
--- a/homeassistant/components/airnow/const.py
+++ b/homeassistant/components/airnow/const.py
@@ -14,10 +14,32 @@ ATTR_API_POLLUTANT = "Pollutant"
 ATTR_API_REPORT_DATE = "DateObserved"
 ATTR_API_REPORT_HOUR = "HourObserved"
 ATTR_API_REPORT_TZ = "LocalTimeZone"
-ATTR_API_REPORT_TZINFO = "LocalTimeZoneInfo"
 ATTR_API_STATE = "StateCode"
 ATTR_API_STATION = "ReportingArea"
 ATTR_API_STATION_LATITUDE = "Latitude"
 ATTR_API_STATION_LONGITUDE = "Longitude"
 DEFAULT_NAME = "AirNow"
 DOMAIN = "airnow"
+
+SECONDS_PER_HOUR = 3600
+
+# AirNow seems to only use standard time zones,
+# but we include daylight savings for completeness/futureproofing.
+US_TZ_OFFSETS = {
+    "HST": -10 * SECONDS_PER_HOUR,
+    "HDT": -9 * SECONDS_PER_HOUR,
+    # AirNow returns AKT instead of AKST or AKDT, use standard
+    "AKT": -9 * SECONDS_PER_HOUR,
+    "AKST": -9 * SECONDS_PER_HOUR,
+    "AKDT": -8 * SECONDS_PER_HOUR,
+    "PST": -8 * SECONDS_PER_HOUR,
+    "PDT": -7 * SECONDS_PER_HOUR,
+    "MST": -7 * SECONDS_PER_HOUR,
+    "MDT": -6 * SECONDS_PER_HOUR,
+    "CST": -6 * SECONDS_PER_HOUR,
+    "CDT": -5 * SECONDS_PER_HOUR,
+    "EST": -5 * SECONDS_PER_HOUR,
+    "EDT": -4 * SECONDS_PER_HOUR,
+    "AST": -4 * SECONDS_PER_HOUR,
+    "ADT": -3 * SECONDS_PER_HOUR,
+}
diff --git a/homeassistant/components/airnow/coordinator.py b/homeassistant/components/airnow/coordinator.py
index 35f8a0e0abf..32185080d25 100644
--- a/homeassistant/components/airnow/coordinator.py
+++ b/homeassistant/components/airnow/coordinator.py
@@ -12,7 +12,6 @@ from pyairnow.errors import AirNowError
 
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers.update_coordinator import DataUpdateCoordinator, UpdateFailed
-from homeassistant.util import dt as dt_util
 
 from .const import (
     ATTR_API_AQI,
@@ -27,7 +26,6 @@ from .const import (
     ATTR_API_REPORT_DATE,
     ATTR_API_REPORT_HOUR,
     ATTR_API_REPORT_TZ,
-    ATTR_API_REPORT_TZINFO,
     ATTR_API_STATE,
     ATTR_API_STATION,
     ATTR_API_STATION_LATITUDE,
@@ -98,9 +96,7 @@ class AirNowDataUpdateCoordinator(DataUpdateCoordinator[dict[str, Any]]):
                 # Copy Report Details
                 data[ATTR_API_REPORT_DATE] = obv[ATTR_API_REPORT_DATE]
                 data[ATTR_API_REPORT_HOUR] = obv[ATTR_API_REPORT_HOUR]
-                data[ATTR_API_REPORT_TZINFO] = await dt_util.async_get_time_zone(
-                    obv[ATTR_API_REPORT_TZ]
-                )
+                data[ATTR_API_REPORT_TZ] = obv[ATTR_API_REPORT_TZ]
 
                 # Copy Station Details
                 data[ATTR_API_STATE] = obv[ATTR_API_STATE]
diff --git a/homeassistant/components/airnow/sensor.py b/homeassistant/components/airnow/sensor.py
index 722c0d6f4a9..1abf93514a5 100644
--- a/homeassistant/components/airnow/sensor.py
+++ b/homeassistant/components/airnow/sensor.py
@@ -4,9 +4,10 @@ from __future__ import annotations
 
 from collections.abc import Callable
 from dataclasses import dataclass
-from datetime import datetime
 from typing import Any
 
+from dateutil import parser
+
 from homeassistant.components.sensor import (
     SensorDeviceClass,
     SensorEntity,
@@ -34,12 +35,13 @@ from .const import (
     ATTR_API_PM25,
     ATTR_API_REPORT_DATE,
     ATTR_API_REPORT_HOUR,
-    ATTR_API_REPORT_TZINFO,
+    ATTR_API_REPORT_TZ,
     ATTR_API_STATION,
     ATTR_API_STATION_LATITUDE,
     ATTR_API_STATION_LONGITUDE,
     DEFAULT_NAME,
     DOMAIN,
+    US_TZ_OFFSETS,
 )
 
 ATTRIBUTION = "Data provided by AirNow"
@@ -69,6 +71,18 @@ def station_extra_attrs(data: dict[str, Any]) -> dict[str, Any]:
     return {}
 
 
+def aqi_extra_attrs(data: dict[str, Any]) -> dict[str, Any]:
+    """Process extra attributes for main AQI sensor."""
+    return {
+        ATTR_DESCR: data[ATTR_API_AQI_DESCRIPTION],
+        ATTR_LEVEL: data[ATTR_API_AQI_LEVEL],
+        ATTR_TIME: parser.parse(
+            f"{data[ATTR_API_REPORT_DATE]} {data[ATTR_API_REPORT_HOUR]}:00 {data[ATTR_API_REPORT_TZ]}",
+            tzinfos=US_TZ_OFFSETS,
+        ).isoformat(),
+    }
+
+
 SENSOR_TYPES: tuple[AirNowEntityDescription, ...] = (
     AirNowEntityDescription(
         key=ATTR_API_AQI,
@@ -76,16 +90,7 @@ SENSOR_TYPES: tuple[AirNowEntityDescription, ...] = (
         state_class=SensorStateClass.MEASUREMENT,
         device_class=SensorDeviceClass.AQI,
         value_fn=lambda data: data.get(ATTR_API_AQI),
-        extra_state_attributes_fn=lambda data: {
-            ATTR_DESCR: data[ATTR_API_AQI_DESCRIPTION],
-            ATTR_LEVEL: data[ATTR_API_AQI_LEVEL],
-            ATTR_TIME: datetime.strptime(
-                f"{data[ATTR_API_REPORT_DATE]} {data[ATTR_API_REPORT_HOUR]}",
-                "%Y-%m-%d %H",
-            )
-            .replace(tzinfo=data[ATTR_API_REPORT_TZINFO])
-            .isoformat(),
-        },
+        extra_state_attributes_fn=aqi_extra_attrs,
     ),
     AirNowEntityDescription(
         key=ATTR_API_PM10,
diff --git a/tests/components/airnow/snapshots/test_diagnostics.ambr b/tests/components/airnow/snapshots/test_diagnostics.ambr
index c2004d759a9..71fda040c1d 100644
--- a/tests/components/airnow/snapshots/test_diagnostics.ambr
+++ b/tests/components/airnow/snapshots/test_diagnostics.ambr
@@ -8,7 +8,7 @@
       'DateObserved': '2020-12-20',
       'HourObserved': 15,
       'Latitude': '**REDACTED**',
-      'LocalTimeZoneInfo': 'PST',
+      'LocalTimeZone': 'PST',
       'Longitude': '**REDACTED**',
       'O3': 0.048,
       'PM10': 12,