OpenWeather (OpenWeatherMap) is the most popular weather API — current conditions, forecasts and historical data — with a free tier big enough for many apps and low-cost paid plans above it. Here's what it costs and how to get your key.
| Plan | Price / month | Calls | Best for |
|---|---|---|---|
| Free cheapest | $0 | ~1,000 / day (60/min) | Hobby apps, dashboards |
| Startup (pay-as-you-go) | metered | beyond free, per-call | Growing usage |
| Developer | $180 | higher limits + endpoints | Production |
| One Call API 3.0 | first 1,000/day free | then ~$0.0015/call | Forecast + history |
→ Bundling several APIs? Total them on the API stack cost calculator.
OpenWeather's free tier gives about 1,000 calls a day (60/min) for current weather and short forecasts — plenty for a hobby app or dashboard — and you only need an email to get a key. Heavier use or premium data (long history, minute forecasts) moves you to a paid plan or the metered One Call API 3.0.
1. Sign up at openweathermap.org.
2. Your API key is under My API keys — copy it (it can take a little while to activate).
3. Call endpoints with appid=YOUR_KEY.
4. Subscribe to One Call 3.0 or a paid plan for advanced data.
Test it with a simple request:
WeatherAPI.com and Tomorrow.io are popular rivals with free tiers; Open-Meteo is fully free and needs no key for non-commercial use; national services (NWS) are free where available.
OpenWeather's free tier is generous for a weather API: around 60 calls per minute with a monthly cap near 1,000,000 calls on the classic current-weather and forecast products. The newer One Call API 3.0 is metered separately, with a default free allowance of roughly 1,000 calls per day that you can raise (with billing enabled) by setting your own daily limit.
Paid subscriptions scale the per-minute rate sharply while keeping the same endpoints:
Go over your allowance and OpenWeather returns an HTTP 429 (and may temporarily block the key), so cache results and respect the per-minute rate. If you are checking OpenWeather API rate limits before launch, note the split model: the classic API is limited by calls-per-minute plus a monthly cap, while One Call 3.0 is billed and capped per day.
See our other data-API guides to compare free monthly quotas before committing a production app to a single weather provider.
Yes — the free tier gives roughly 1,000 calls a day for current weather and basic forecasts, with just an email to sign up.
Either pay-as-you-go per call (One Call API 3.0, ~$0.0015/call after the first 1,000/day free) or a fixed plan like Developer for higher limits and more endpoints.
Sign up at openweathermap.org and copy the key from 'My API keys' — allow some time for it to activate.
Open-Meteo is free and keyless for non-commercial use; WeatherAPI.com also has a free tier.
Not affiliated with OpenWeather. Prices are reference estimates — always verify on the official pricing page.