The 12-month pest calendar.
When each pest is most active across the year — calibrated for temperate-climate U.S. zones. Use it to time inspections before peak pressure, schedule bait rotations, and stop treating things that are about to go dormant on their own.
How to use the calendar
The calendar is most useful as a planning tool, not a real-time monitor. Three patterns to look for:
- Pre-peak interventions. If a pest peaks in July, the most effective interventions happen in April or May — exclusion before the population is high, baits in place before recruitment kicks in.
- Off-season treatment is often wasted. Treating for wasps in November or for mosquitoes in February rarely helps. Save the time and budget for when the pest is actually active.
- Inverse patterns matter. Rodents and silverfish push into homes as outdoor temperatures drop — exclusion work in September pays off for the entire winter.
Region notes
This calendar reflects temperate U.S. conditions — roughly USDA hardiness zones 5 through 7. Adjustments by climate zone:
- Deep South (zones 8–10): Active seasons start 4–6 weeks earlier and end 4–6 weeks later. Termite and mosquito pressure are essentially year-round. German cockroach activity peaks 6+ months per year.
- Pacific Northwest: Slugs, ants, and dampwood termites have extended seasons due to mild wet winters. Mosquito pressure is lower than in the East but still meaningful in late summer.
- Northern tier (zones 3–5): Active windows compress. Outdoor pests (mosquitoes, ticks, wasps) operate roughly May–September. Indoor pests (rodents, cockroaches, silverfish) peak in late fall as outdoor populations seek shelter.
- Arid Southwest: Lower mosquito and ant pressure; higher scorpion, cockroach, and rodent pressure. Termite pressure is significant year-round in many areas.
Why the calendar matters more than people think
Most pest control is reactive: you see the pest, you call someone, treatment happens. The calendar lets you reverse that — to put exclusion in place in September instead of trapping mice in January, to inspect for termite swarmers in late April instead of finding damage in October, to drain mosquito breeding sites in March instead of fogging in July.
It's also the single best argument against year-round pesticide service contracts that don't actually align with pest biology. If you're paying for quarterly outdoor spray applications in January in zone 5, you're paying for theater. A licensed professional with a real program adjusts treatment by season — and so should you.