Open-Meteo is an open-source weather data API that serves forecasts and related environmental datasets via a simple HTTP JSON interface. It aggregates and processes numerical weather prediction data from multiple national weather services and can be run as your own API instance.

Key Features

Hourly weather forecasts for up to 16 days
Historical weather data spanning decades (hourly, global coverage)
Multiple model sources and intelligent selection depending on location and region
Additional APIs such as marine weather, air quality, geocoding, elevation, and flood-related data
High-performance responses designed for low-latency use
No API key required for the public non-commercial endpoint; CORS supported
Container-friendly deployment options for running private instances

Use Cases

Powering weather features in mobile apps, websites, and dashboards
Data pipelines and analytics using historical climate and weather time series
Feeding forecasting, automation, or smart home workflows with reliable hourly weather inputs

Limitations and Considerations

Public API usage is intended for fair-use and non-commercial scenarios; higher-volume and commercial use may require a subscription
Data coverage, resolution, and update frequency vary by underlying regional and global models

Open-Meteo is well-suited for developers who want a transparent, auditable weather backend with a straightforward JSON API. It is especially useful when you need reproducible processing and the option to operate your own infrastructure for scale or specialized workloads.