I had initially read a review stating this ran a little small, so I almost ordered the 24 month sz for my 18 month old... I'm glad I stuck with the 18month sz. My daughter is 23lbs and 30" long, for reference. This jacket still has plenty of room for her to grow into, but a 24 month sz would have been ridiculously large for her!  The jacket seems cozy (tested for the first time on a breezy, drizzly morning at 45 degrees), and I really appreciate the soft yet snug elastic at the wrists and the elastic around the hood (b/c it's son annoying when hoods just slide or blow off - what's the point of a hood after all?!). Since fleece is relatively water resistant anyway, I don't know that the extra top panel of waterproof material is really needed or that helpful, but it is cute :) I am very pleased with this purchase & highly recommend it!