General information
How would you differentiate Google's Weather API from specialized weather data vendors?
Google is integrating technology from our reputable weather company acquisition with advancements from Google DeepMind's MetNet and WeatherNext AI models (2025). This leverages the proven reliability of the Google Maps Platform.
What is the difference between WeatherNext (GraphCast/GenCast) forecast datasets and Google's Weather API?
Google's weather product suite offers a comprehensive range of solutions for diverse needs. WeatherNext models provide raw, AI-based model forecast outputs ideal for research, modelling (for example, operational decision models), and analysis. They are made available using open-source code and historical and current weather datasets on Earth Engine and BigQuery.
The GMP Weather API delivers weather data for current conditions, hourly forecasts, and daily forecasts using both AI and traditional forecasting systems (such as numerical weather prediction). It comes in a developer-friendly format that seamlessly integrates into apps and web services.
This dual approach caters to both specialized research needs and broad developer accessibility, maximizing the impact and reach of Google's weather capabilities.
API usage
What is the Weather API coverage?
The Weather API supports all countries globally except Japan, Korea, and prohibited territories. For our initial launch, we are supporting populated areas (excluding remote locations such as the middle of the ocean, deserts, and mountain tops). We are planning continuous resolution and quality improvements through 2025.
What is the spatial granularity of the Google Weather API?
Data resolution is such that forecasts are created within a few kilometers for any location globally.
What is the update frequency for the Weather API?
| Endpoint | Current conditions | Hourly forecast | Daily forecast | Hourly history |
|---|---|---|---|---|
| Refresh rate | 15 minutes (periodically within the hour) | 30 minutes (periodically within the hour) | 30 minutes (updated at the same time as hourly forecast) | Twice a day (7 AM and 7 PM Pacific Standard Time). |
Does the Weather API provide nowcast precipitation forecasting?
Google doesn't provide nowcast forecasting (minute forecast) in the API, but it does provide current conditions, hourly forecasts, and daily forecasts.
Does the Weather API provide separate UVA and UVB values?
UV Index is a single index which combines both UVA and UVB. We don't provide a breakdown by component.
How does the Weather API produce a forecast output?
As shown in the diagram below, Weather API forecasts are created from an internal forecasting system that utilizes weather models and observations from global weather agencies as inputs. Data from public ground-truth weather sensors are used to improve the forecast model.
What is the accuracy? How does Google evaluate and measure accuracy performance of the Weather API?
Data resolution is such that forecasts are created within a few kilometers for any location globally, and in higher resolution in the US and Europe. The ongoing quality of the data is maintained through continuous internal monitoring of the forecast quality when compared to observations from the highest quality weather stations.
Based on internal reports, our temperature root mean square error (RMSE) in degree Celsius at CONUS versus ground truth is less than 2.2°C for 1-2 day forecasts and less than 2.9°C for 5 day forecasts.
Disclaimer: This statement is based on an internal report that was generated in May 2024. Google can make changes and continuously improve its forecasting techniques, and RMSE is subject to specific weather patterns, so these RMSE results may change over time.
Additionally:
- We generate real-time forecasts for tens of millions of points to provide hyperlocal weather forecasts almost everywhere in the world.
- Our models produce a higher quality forecast for variables such as temperature, dewpoint and others compared to existing numerical weather prediction models based on ground-truth comparisons.
- We're constantly validating and improving our models to ensure that we're providing a state-of-the-art forecast.
API limits and access
Is there a rate limit on the API?
For the GMP Weather API, there is a default rate limit of 6,000 queries per minute.
Can I access the data in bulk?
Bulk data is not available. You can query Weather API within the quota (6,000 QPM) and respect caching terms outlined in the Terms of Service.
Do I have to enable billing?
A valid billing account is required to use the Weather API. See Enable billing to set up your project with a billing account.
What happens if I query a location that is not supported?
If the latitude and longitude are not covered in the supported country list, the response will return a 404 error code with the message, "Information is unavailable for this location. Please try a different location."