Paste the code below where you want it. It updates itself every three hours, costs nothing, and needs no account or key.
Free for any non-commercial site, as long as the credit line stays visible. The forecast data comes from Open-Meteo and the national weather services under CC BY 4.0, and the widget carries that attribution for you. The two lines of script only fit the frame to its content; if your site strips scripts, the frame still works at a fixed height.