I'd like to know if the AccuWeather API is free for commercial use. If not, how I can use it for commercial purposes?
Is there a totally free weather API that I can use for my app?
Accuweather data is not free. They will quote you for a custom service if you call their sales support. At one of my previous companies (circa 2007), we were able to get a contract with them for national hourly weather across their station network very cheap, but still not free.
If you are looking for free weather APIs, Please have a look at weather underground.