Pokémon GO has locked in key dates for its next Season, with Community Days scheduled for June 20, July 4 and August 15. Additional events include Raid Days on June 27 and August 22, a Hatch Day on August 8 and a still unannounced event set for July 18. The lineup gives players a clear roadmap for the summer, with regular chances to catch featured Pokémon, take on raids and make the most of limited time bonuses spread throughout the season.
Source: Official Pokémon GO blog and Pokemon.com