Best Free Weather APIs for Developers in 2026

Building a weather app or adding weather data to your project? Finding a reliable free weather API can be challenging. After testing dozens of options, here are the best ones that actually work in production.

Why Weather APIs Matter

Weather data enhances user experience in travel apps, agriculture platforms, logistics systems, and smart home applications. A good weather API should provide accurate data, reliable uptime, and a generous free tier.

Top 3 Free Weather APIs

1. WeatherStack

Real-time weather conditions with 1,000 free requests per month. Supports both metric and imperial units, making it perfect for global applications.

curl "https://freeapitools.dev/api/v1/weather?city=Tokyo&units=metric"

View WeatherStack documentation →

2. ForecastPro

Get 7-day weather forecasts with hourly precision. Includes precipitation probability, UV index, and air quality data. 500 requests/month free.

curl "https://freeapitools.dev/api/v1/forecast?lat=35.6762&lon=139.6503&days=7"

View ForecastPro documentation →

3. AirQualityAPI

Focus on air quality with global AQI, PM2.5, PM10, and pollutant data. Includes health recommendations based on current conditions. 2,000 free requests monthly.

View AirQualityAPI documentation →

Getting Your API Key

All three APIs use the same authentication system. Get your free API key to start making requests:

curl -X POST https://freeapitools.dev/api/auth/key \
  -d '{"email": "your@email.com", "project": "weather-app"}'

Read the quickstart guide →

Conclusion

For most developers, WeatherStack offers the best balance of features and free tier limits. If you need detailed forecasts, ForecastPro is your best bet. For environmental monitoring, go with AirQualityAPI.