The little-known map is actually tucked away inside a stock Apple app.
And it's essential for anyone who loves (or hates) a wintry snowfall.
You'll find the map in Apple's Weather app.
The app used to be mocked for being rubbish, but it's received huge updates making it significantly better.
It's partly linked to the fact that Apple bought up beloved weather app Dark Sky and appears to have used some of that tech to improve Weather.
There are loads of changes to Weather in the latest update, but one of the best features is the snow map.
And with winter now upon us in the UK and US, it's certainly one to keep an eye on.
First, you'll need to make sure you're using a fairly recent version of Apple's iPhone software: iOS 15.
