San Diego County doesn't have a harsh winter that kills off pest populations — which means pest season here never truly ends. Different pests peak at different times of year, and knowing what to watch for each season helps you stay ahead of problems before they start. Here's a season-by-season guide to pest activity in San Diego County.
Spring: Ants and wasps wake up
As temperatures warm, ant colonies become active and start sending scouts indoors in search of food. Spring is also when wasp and bee activity picks up, with swarms looking for new nesting sites. This is the ideal time to establish a perimeter treatment and seal entry points before ant trails form.
Summer: Mosquitoes, spiders, and peak ant season
Summer is the busiest pest season in San Diego. Mosquitoes breed rapidly in any standing water, spiders are active and building webs around eaves and patios, and ant activity peaks. Barrier spray treatments for mosquitoes and quarterly perimeter service for ants and spiders keep activity under control through the hottest months.
Fall: Rodents move indoors
As evenings cool, roof rats and mice start looking for warm, sheltered nesting sites inside homes. Fall is the time to inspect for and seal entry points, set up exterior bait stations, and confirm attic and crawl space areas are secure. Sealing gaps before rodents find them is far easier than removing an established infestation.
Winter: Overwintering pests and rodents
Winter in San Diego is mild, but rodents that moved in during fall remain active indoors. Some insects, like certain spiders and occasional invaders, also seek shelter inside. Winter is a good time for interior inspections and for maintaining exterior bait stations so rodent populations don't rebound in spring.
Year-round protection
Because San Diego's pest pressure is continuous, the most effective approach is year-round prevention. A quarterly service plan adapts treatments to the season — ant perimeter in spring and summer, mosquito barrier in summer, rodent monitoring in fall and winter — so your home stays protected no matter what's active.
When to call a professional
If you're seeing seasonal pest activity that DIY products aren't controlling, a professional can tailor a plan to your home and the pests common to your part of San Diego County. Same-day service is available for urgent problems.
