It's everyone I believe, June is usually a rainy month. Gotta say I don't mind it all too much, it'd be quite boring being bright blue skies and sunny all day. Plus, it let's me use my fab leaf umbrella <3
I'm pretty sure it rains a lot more in June and April (because of April showers and all). July is when it'll get all Summery and sunny, so just you wait! c: I'll be missing the rain when that happens.
It's been raining a lot in my town as well-usually every other day. I don't mind it too much, since it's probably just a rainy season, but I'll be glad when summer comes around.
Yes, I know that the game was made in Japan, but in most of the Northern hemisphere, summer has less rain than other months (even when it's still rainy, it rains less). Some parts of the world even experience droughts during that time.
It's not so much that I mind the rain in the game but that it's annoying that it happens so much in the summer and less in other months. Since they're going for a cartoonish thing they could have just made the seasons the stereotype of what those seasons are in most cartoonish material.
If not, it would be awesome if they'd let you pick a climate for your town, so you could make it match your real-life climate or the climate that your town has in your head. In mine it'd make more sense for it to rain year-round, for example.