The application weather data is directly retrieved from Weather Underground. It has nothing to do with the controller except for the actual watering level. In fact, here is the code: https://github.com/OpenSprinkler/OpenSprinkler-App/blob/master/www/js/main.js#L2957-2973
You can see which values I am using from the Weather Underground reply, without any modification. Therefore, I really can’t help describe any differences you are seeing between their website and the application output as the data is directly from Weather Underground.
If you can use the above links and information to find an error or incorrect value being used please let us know so we can resolve it.
Thank you!