Weather Underground is claimed to be the internet’s first online weather service. It is a proprietary weather service that is based on actual cumulative community based weather data points.
I recently came across a code that I was able to use to get a one year ad free subscription to their service. I am also seeing where people were able to use the code to renew their subscription, as well. It is my thinking they have this code floating out there as a promotional gimmick. If you get this to work on your computer and you are also an Android user, you can download/install the Weather Underground App (from the Google Play Store), log in with your credentials, and you will also have an ad free experience on your Android device, as well.
You initially have to sign up for an account, for which you will be sent an email confirmation that will allow you to login to the account. It was after I logged into my account and went to the membership services that I was able to enter the code. Hope this works for you as well; as, Weather Underground is a great weather service.