type: service
status: active
timestamp: 2026-06-20
tags: [services, data-api, weather, open-meteo, primary]

Open-Meteo

Free unlimited weather API — no auth, no API key, no card

Open-Meteo

Role

The family’s locked weather data source. When any site needs forecast / current-conditions / historical weather (none today — locked as the approved choice for when the need lands), it calls Open-Meteo. Picked over OpenWeatherMap, WeatherAPI, Tomorrow.io, and Visual Crossing on free-tier generosity + no-auth + no-card grounds.

Free tier

Unlimited requests for non-commercial use (soft cap ~10,000 requests/day before the operator nudges)
No API key, no auth header — REST calls are anonymous
No card at any point
Forecast (up to 16 days ahead), current conditions, historical archive (1940 → present), marine, air quality, climate change scenarios, all on the same free envelope
JSON responses, predictable schema, multi-model ensemble

Card / subscription required?

NO. Anonymous public API. No sign-up, no API key, no billing relationship. Pure HTTP fetch() against https://api.open-meteo.com/v1/forecast?....

Use shape

const r = await fetch(
  'https://api.open-meteo.com/v1/forecast?' +
  new URLSearchParams({
    latitude: '12.97',
    longitude: '77.59',
    current: 'temperature_2m,weather_code',
    timezone: 'auto',
  }),
);
const { current } = await r.json();

Cache aggressively at the CF Worker edge: 1-hour TTL on forecast, 24-hour TTL on historical. Per data-apis-open-meteo-alpha-vantage, the umbrella Hono Worker fronts every weather call with a Workers KV cache so realistic family-wide load stays well under the soft cap.

Why this is our pick

No API key removes a secret-rotation surface — nothing to put in Doppler, nothing to leak.
Unlimited free removes the never-hit-quotas worry on the provider side; CF Worker quota is the only cap to manage, and the existing CF Worker quota mitigation playbook covers that surface.
Multi-model ensemble — the response averages forecasts from GFS / ECMWF / GEM / UKMO / Météo-France, which is the highest-quality forecast-on-the-free-tier the family found.
Open — Open-Meteo’s data and APIs are CC BY 4.0, mirrors the family’s everything-is-public-OSS posture.

Alternatives

OpenWeatherMap — 1,000 calls/day free, requires API key, geocoding bundled. Rejected on key-rotation overhead and tighter cap.
WeatherAPI.com — 1M calls/month free, requires API key. Higher cap than OWM but still narrower than Open-Meteo’s unlimited.
Tomorrow.io — 500 calls/day, requires card after trial. Rejected on no-card-on-file.
Visual Crossing — 1,000 records/day free, requires card past trial. Rejected on the same grounds.
NOAA / NWS direct (US only) — free, no key. Geo-restricted so doesn’t cover the family’s international audience.

Swap cost

Low — Open-Meteo’s response shape is JSON with predictable keys; remapping to OpenWeatherMap / WeatherAPI is a per-field transform in the umbrella Worker. No client SDK lock-in.

Cross-refs

Edit on GitHub · Back to index