Add Google Air Quality integration (#39107)

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source/_integrations/google_air_quality.markdown

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+---
+title: Google Air Quality
+description: Instructions on how to integrate Google Air Quality into Home Assistant.
+ha_category:
+  - Sensor
+ha_release: 2025.12
+ha_iot_class: Cloud Poll
+ha_config_flow: true
+ha_codeowners:
+  - '@Thomas55555'
+ha_platforms:
+  - sensor
+ha_integration_type: integration
+ha_domain: google_air_quality
+ha_quality_scale: bronze
+---
+
+The **Google Air Quality** {% term integration %} provides Air quality data through the Google Air Quality API.
+
+## Prerequisites
+
+You need an API key. Follow the instructions [in the Google developer documentation](https://developers.google.com/maps/documentation/air-quality/get-api-key) for creating an API key.
+Additionally, you have to create a *Billing Account*. At the time of writing this documentation, Google allows 10,000 API calls per month for free.
+
+{% important %}
+This integration polls every 60 minutes. Here is an overview about how many API calls are performed per month in dependence of the amount of coordinates:
+
+Coordinates | API calls per month
+----------- | -------------------
+1           | 800
+2           | 1,600
+3           | 2,400
+4           | 3,200
+5           | 4,000
+10          | 8,000
+12          | 9,600
+
+Consider each restart of Home Assistant is an additional API call, per coordinate/entry.
+
+You can set up a [budget](https://cloud.google.com/billing/docs/how-to/budgets) for your billing account. This does not limit your costs, but you can get an alert when you reach the budget.
+You may want to setup [disable billing with notifications](https://cloud.google.com/billing/docs/how-to/disable-billing-with-notifications). This can still produce costs between incurring costs and receiving budget notifications.
+
+Make sure to monitor the cost. If you make too many requests, you will be charged for it. The integration cannot monitor it for you.
+{% endimportant %}
+
+{% include integrations/config_flow.md %}
+
+## Supported functionality
+
+### Sensor
+
+The integration will create the following sensors:
+For your local air quality you can find more details [here](https://developers.google.com/maps/documentation/air-quality/laqis)
+
+- **Universal Air Quality Index (UAQI)**  
+  *The global air quality index provided by Google. Ranges from 0 (worst) to 100 (best).*
+
+- **UAQI Category**  
+  *Descriptive category for UAQI. Possible values include: Excellent air quality, Good air quality, Moderate air quality, Low air quality, Poor air quality.*
+
+- **UAQI Dominant Pollutant**  
+  *The pollutant that most significantly influences the UAQI value. Possible values include: PM2.5, PM10, Ozone (O₃), Nitrogen Dioxide (NO₂), Sulphur Dioxide (SO₂), Carbon Monoxide (CO)*
+
+- **Local Air Quality Index**  
+  *A regionally calibrated AQI value, where available.*
+
+- **Local Category**  
+  *Descriptive category for the local AQI. The values can differ from the ones set as UAQI Category.*
+
+- **Local Dominant Pollutant**  
+  *The pollutant that most significantly influences the local AQI. The values can differ from the ones set as UAQI Dominant Pollutant.*
+
+- **PM2.5**  
+  *Particulate matter smaller than 2.5 µm in diameter.*
+
+- **PM10**  
+  *Particulate matter smaller than 10 µm in diameter.*
+
+- **Ozone (O₃)**  
+  *Ground-level ozone concentration.*
+
+- **Nitrogen Dioxide (NO₂)**  
+  *Nitrogen dioxide concentration.*
+
+- **Sulphur Dioxide (SO₂)**  
+  *Sulphur dioxide concentration.*
+
+- **Carbon Monoxide (CO)**  
+  *Carbon monoxide concentration.*
+
+## Removing the integration
+
+{% include integrations/remove_device_service.md %}
+