You know that Summer has arrived when...

when all the tough guys who hide from a little weather, come out to harrass people.
when people start wearing as little as they can get away with wherever the can do so. (this is mostly a good thing, though the human appearance isn't always flattered by it)

birds and flowers of course though that's more of a spring thing. flowers to attract the bugs and birds to eat them. the bugs get more noticable as summer wears on.

the long vacation from school is mostly a good thing for them. (i meant children and adolescents, not so much bugs, for whom it is THE time)

summer isn't really my most favorite time of year.
spring makes me happy though, and right now it is still mostly spring where i am.