For the life of me, I cannot find any way to cancel. I've checked on the webapp, on my phone's app, via my mobile playstore, via my Google Account subscription manager both on my phone and desktop -- nothing on any of those locations.
When searching to answer my own question, I couldn't find a clear answer, and it looks like this is a common problem that people have.
Can someone please help me? I like Windy but I simply do not need or want the subscription anymore.