I live in the midwest and our summers get pretty hot and humid. That said, we keep the house between 68 (at night) and 72 (daytime) during the summer. That combined with my tank being in the basement, I don't even need to use a fan with my MH/LED (actinic) combination to keep temp levels stable. 40 breeder with (1) 175 watt 10K MH and (1) 36" actinic LED strip light.