World Time & Weather
Current weather, local time, UTC offset and DST rules for 400 cities as static JSON
Weather in your terminal, supports JSON output.
wttr.in API is a free Weather API that requires no API key, is served over HTTPS and supports CORS, so it can be called from the browser.
Details from wttr.in.

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Current weather, local time, UTC offset and DST rules for 400 cities as static JSON
The wttr.in API is provided by wttr.in (wttr.in).
Yes. The wttr.in API is listed in the Weather category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
No. The wttr.in API requires no authentication, so you can start making requests without signing up.
Yes. The wttr.in API supports CORS, so front-end JavaScript can call it directly.
Yes. The wttr.in API is served over HTTPS, so it's safe to use in production.