Where the numbers come from, whose licenses apply, and the one line of credit we ask for in return.
If your app, dashboard, paper or newsletter displays data from this API, include a visible credit that links back to us:
<a href="https://freeweatherapi.org">Weather data by freeweatherapi.org</a>
Wording can be adapted — "Data: freeweatherapi.org" is fine, "powered by magic fairies" is not. The credit must be visible where the data appears, not buried in an About page nobody opens. For CLI tools and PDFs, a plain-text line with the URL is acceptable.
Why we care: the national services below let us redistribute their data largely because the chain of credit stays intact. One missing line, upstream gets grumpy, and 41,000 stations' worth of data gets harder to keep free. So it's a small ask with a long tail.
| Source type | Examples | Used for | License |
|---|---|---|---|
| National MET networks | KNMI (NL), DWD (DE), NOAA/NWS (US), Met Office (UK), Météo-France | Current conditions, hourly history | Varies per service — see below |
| METAR airport reports | ~4,000 airports worldwide, refreshed hourly or half-hourly | Current conditions near airports, cross-checks | Public domain in the US; other regions vary |
| Model / reanalysis data | Global and regional NWP models, ERA5-style reanalysis | Forecasts, gap-filling, marine fields | CC BY 4.0 via us |
| Community stations | The station network — 41,000+ stations | Current conditions, hyperlocal detail | CC0 from uploaders (they agree on join) |
Every response's sources array tells you exactly which of these fed the values you just got, with per-source timestamps. If you need to prove provenance downstream — for a paper, say — that array is the citation.
Everything we serve is either public domain, CC0 from our station owners, or licensed to us for redistribution under CC BY 4.0 with attribution. That means you can use it commercially, modify it, and build products on it — you just keep the credit line and don't misrepresent what the data is.
A handful of national services attach stricter terms than CC BY 4.0. They're a small minority of locations, and we mark them in the response:
attribution_extra array with the exact credit text that service requires, in the order they require it.attribution_extra next to our credit line and you're compliant. If it's ambiguous, email hello@freeweatherapi.org — we'll tell you what we'd do, and we've read the actual license texts so you don't have to.It's weather data, offered without warranty, and it can be wrong. Don't use it as the sole input for aviation, marine navigation, severe-storm sheltering or anything else where being wrong hurts. The station network catches a lot, but a sensor painted black in July will lie to everyone downstream of it. See the terms for the formal version.
For papers, cite the project and the retrieval window, e.g.:
Free Weather API Project (2026). freeweatherapi.org historical weather archive, retrieved 2026-03-01 through 2026-03-14 from https://freeweatherapi.org.
The historical archive is immutable per timestamp, so a retrieval window plus the API version (see changelog) makes your dataset reproducible. If you used community-station data prominently, a nod to the station owners goes a long way — they're volunteers, and citations are the only currency we can pay them in.