Re: I already have an IoT standard
Depends where you live. In some places (generally flat, open, places), you can look up, work out which way the clouds are moving, look at the opposite horizon and get an idea of what the weather is going to be doing for the rest of the day.
In other places, looking at the sky will give you maybe ten minutes warning of what's coming, and the weather could be completely different by the afternoon. Yes local knowledge can help, but often all it can tell you is that "the weather is going to be changeable".