Pirate Weather: A free, open, and documented forecast API
I was really hoping <a href="https://merrysky.net/" rel="nofollow">https://merrysky.net/</a> had a graphical forecast similar to weather underground's 10 day. I've yet to find anything else that quickly shows everything you'd want to know in a single image. Even the mouseover timeline is perfection. It is so good and seemingly exclusive to WU that I sometimes wonder if they hold a patent for it.