If I were to create anthropomorphic representations the seasons, I would absolutely make Spring the cutest, so NHK and I are on the same page here. Recently, they've started using cute anime-styled characters to represent seasonal weather during forecasts, and Haru-chan (or Spring-chan) is even more moe than Nia from Tengen Toppa Gurren Lagann. Winter looks a little scary, but to tell you the truth, based on the amount of snow I had to shovel this winter, he should be.

Oh, and keep in mind that they did not stop at the four seasons- no, even quasi-seasons like "early summer" got their own munchkins. Quite thorough.

I don't mind this sort of thing, but I'm afraid that this group of characters might become so popular that they'll get their own anime- which I will then have to recap for Annotated Anime, in all likelihood. Can you imagine? "This week, Spring-chan and Fall-chan got into a fight over which season was better for playing catch, but old man Winter-dono had other ideas!"....Oh my God, I think this is a prophecy. I think I have become psychic, and this is honestly going to happen. I'm scared. I apologize for every bad thing I ever said about Ladies vs. Butlers.

If you doubt the allure of the Weather-chans, you can go here and here for some lovely images and fanart. Perhaps ironically, whoever did that "NHK-ON!!" image was inspired.