Gran Canaria is a lot of fun in July with water and apricot festivals, the Fiestas del Carmen marine parades and firework displays, and a series of local fiestas or romerias. Here's a guide to July events in Gran Canaria.
Gran Canaria's summer fiesta season is in full swing in June with over a dozen local romerías. You also have bonfires and local beach parties, a bikini fashion show, and Las Palmas' foundational celebrations.
UPDATED 03/04/2017: Gran Canaria in April smells of sweat and cheese (and sunscreen, of course) thanks to the Guia cheese festival and the Mogán triathlon. You can also visit a couple of local fiestas close to the resorts.