Those lazy, hazy, crazy days of summer (can't remember the artist but it was early '60s)
Summer in the City (Lovin' spoonful?) late '60s
Dancing in the city (Marshall, Hain) 1978
Sealed with a kiss (Bryan Hyland?) about 1962
Sorry to be a bit vague about this but I'm at my office desk and all my reference books (and my record collection!) are at home....
The early 1960s were a particularly fruitful time for summer-themed songs. The problem was, most of them were from the U.S. and by the time they came over here, most of them charted in September/October, and summer was over!