When does the weather take place in Seasons?

[Cassie]

The snow should come within 3 days. The seasons are very random and weather can constantly change so you can't know for sure what the weather will be like. You can check the weather channel on TV but it's not always 100% correct.

Sometimes it snows in Spring too. If you put your Sim outside in a swimsuit in the snow you'll have them get cold pretty quickly. Like, when it's fully snowy [the second layer, not the first layer of snow]. Get them to make snow angels and it'll happen even quicker. Nothing's gonna happen when you put a Sim in it's swimsuit in Autumn 'cause it's not cold enough. Wait for the snow. :]