In the latest Mozilla Firefox 127 release simply do the following:

  • Go to about:config in a new tab
  • ‘Accept Risk and Continue’
  • Search for browser.newtabpage.activity-stream.system.showWeather
  • Double-click the result to enable the feature
  • @Vash63
    link
    105 months ago

    Knowing Mozilla it’s probably done client side (meaning it sends weather data for all major regions or something and the client filters what is needed)