From 9ed6b591a5e13b4dd332213a546f3b47dc3e1e50 Mon Sep 17 00:00:00 2001
From: wittypluck <wittypluck@users.noreply.github.com>
Date: Mon, 9 Jun 2025 19:55:09 +0200
Subject: [PATCH] Fix CO concentration unit in OpenWeatherMap (#146403)

---
 homeassistant/components/openweathermap/sensor.py          | 3 +--
 tests/components/openweathermap/snapshots/test_sensor.ambr | 4 ++--
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/homeassistant/components/openweathermap/sensor.py b/homeassistant/components/openweathermap/sensor.py
index 789e9647f77..87b7860afb5 100644
--- a/homeassistant/components/openweathermap/sensor.py
+++ b/homeassistant/components/openweathermap/sensor.py
@@ -10,7 +10,6 @@ from homeassistant.components.sensor import (
 )
 from homeassistant.const import (
     CONCENTRATION_MICROGRAMS_PER_CUBIC_METER,
-    CONCENTRATION_PARTS_PER_MILLION,
     DEGREE,
     PERCENTAGE,
     UV_INDEX,
@@ -170,7 +169,7 @@ AIRPOLLUTION_SENSOR_TYPES: tuple[SensorEntityDescription, ...] = (
     ),
     SensorEntityDescription(
         key=ATTR_API_AIRPOLLUTION_CO,
-        native_unit_of_measurement=CONCENTRATION_PARTS_PER_MILLION,
+        native_unit_of_measurement=CONCENTRATION_MICROGRAMS_PER_CUBIC_METER,
         device_class=SensorDeviceClass.CO,
         state_class=SensorStateClass.MEASUREMENT,
     ),
diff --git a/tests/components/openweathermap/snapshots/test_sensor.ambr b/tests/components/openweathermap/snapshots/test_sensor.ambr
index cbd86f14676..11a1feb721f 100644
--- a/tests/components/openweathermap/snapshots/test_sensor.ambr
+++ b/tests/components/openweathermap/snapshots/test_sensor.ambr
@@ -86,7 +86,7 @@
     'supported_features': 0,
     'translation_key': None,
     'unique_id': '12.34-56.78-co',
-    'unit_of_measurement': 'ppm',
+    'unit_of_measurement': 'µg/m³',
   })
 # ---
 # name: test_sensor_states[air_pollution][sensor.openweathermap_carbon_monoxide-state]
@@ -96,7 +96,7 @@
       'device_class': 'carbon_monoxide',
       'friendly_name': 'openweathermap Carbon monoxide',
       'state_class': <SensorStateClass.MEASUREMENT: 'measurement'>,
-      'unit_of_measurement': 'ppm',
+      'unit_of_measurement': 'µg/m³',
     }),
     'context': <ANY>,
     'entity_id': 'sensor.openweathermap_carbon_monoxide',