When building Weather & Clock Dashboard — a Firefox new tab extension — one of my core requirements was: no user accounts, no API keys, no data sent to my servers .

This post covers how I achieved that using Open-Meteo, a completely free weather API.

Why Open-Meteo?

Most weather APIs require:

Registration + API key management

Rate limits tied to an account

Potential privacy concerns about who's tracking what

Open-Meteo requires none of that. It's:

100% free (10,000 requests/day without an API key)

No registration needed

Open-source

GDPR-compliant by design

The Approach

The extension uses the browser's built-in Geolocation API to get coordinates, then makes a simple HTTP request to Open-Meteo.

Step 1: Get user location

navigator . geolocation . getCurrentPosition ( ( position ) => { const { latitude , longitude } = position . coords ; fetchWeather ( latitude , longitude ); }, ( error ) => { console .…