I guess it's neat, but I don't see the point. 99% of my maps usage is local navigation, mostly in the car. I already know the weather.
The remaining 1% is using the app like an atlas, I guess it's nice to know that it's snowing today in Estonia, but that's not why I'm looking at the place in Google maps.
This implementation doesn't seem particularly useful. However, I have long wanted maps to generate a weather forecast along route for long winter road trips. It can be pretty tedious to look up weather forecasts along a long drive and try to figure out if you'll encounter snow.