[Rainbow Dash looks like she's about to make a comment, but instead changes her mind.]

Hm, well okay! First thing you gotta know about rain, is that us Pegasus have a schedule to keep when it comes to emptying out rainclouds. The plants need it to grow and stuff, so if we wait too long then the rain comes down really hard - and no pony wants to get caught in that. You'll get completely drenched if you stand out there too long.

But what's really cool after a hard rainstorm is the rainbow that appears in the sky afterward. We make those too!