In September, school starts.
Many kids are sad to have to go back to school, so their sadness manifests as rain.
Eventually the kids get so tired of school that they start wishing for snow days.
Sometimes they wish so hard that it actually happens, but it takes a lot of wishing to get snow, so it doesn't happen for a while.
(But what if it ends up snowing on days where you want to go to school? Well, it's either because some other class had a big test or something they wanted to miss, or it's simply because snow wishes are fairly imprecise, and the snowstorm intended for a big test or assignment due date ends up coming a day early or a day late.)
(But then why do some regions get more snow than others? Depends on how good the kids are at wishing. In regions where they're really bad at wishing for snow, there is no snow. In regions where they're really good at wishing for snow, there's lots of snow, but this sort of backfires—those regions then get ways of opening school even when it snows, which increases the amount of wishing required to cancel school without getting much benefit compared to low-snow areas.)
Eventually, though, the kids start getting hopeful that some day soon they'll put an end to this school stuff.
And hope brings out the sun!
The teachers and principals see this sun, see this hope, and they realize that they won't succeed at making more kids' lives miserable much longer.
So they give up and let school out.
But, of course, teachers never learn (that's a student's job, remember?), so in a few more months they'll decide to try again. And there are new students, who haven't learned to get sun rather than snow, so the cycle just repeats.
So the moral of this story? Have hope, because hope causes sun, and sun defeats teachers.
(For completeness, teachers defeat students and students defeat sun.)