Austin’s mosquito season is longer than most Texas residents expect and longer than most pest control calendars account for. Based on Travis County Public Health surveillance data and GreenGuard USA’s field observations across hundreds of Austin-area properties, here’s the realistic month-by-month forecast.
The Short Answer
Austin mosquito season: mid-February through mid-November
That’s approximately 9 months. The peak is May through September, but meaningful mosquito pressure exists from early spring through late fall in most years.
Month-by-Month Forecast
January–February: Low Activity, But Not Zero
Status: Minimal What’s happening: Overwintering tiger mosquito eggs begin hatching when soil temperatures reach 50°F consistently — which in Austin can happen as early as late January during warm spells. Adult mosquitoes from late-hatching populations can remain active through mild January days.
What to do: This is the best time to address standing water sources before the season starts. Fix drainage issues, clean gutters, remove leaf litter from drainage areas. Starting a CO₂ trap in February gives it time to build effectiveness before peak season.
March: Early Season Begins
Status: Building What’s happening: Aedes albopictus (tiger mosquito) adults emerge as daytime temperatures hit 60°F. Container breeding begins. Activity is concentrated near standing water sources — clogged gutters, neglected pots, low drainage areas.
What to do: Install CO₂ trap NOW if you haven’t. Starting before the population peaks gives the trap 6–8 weeks to suppress the breeding cycle before summer. Deploy Bti (mosquito dunks) in any standing water.
April: Accelerating
Status: Moderate What’s happening: Tiger mosquito populations growing rapidly. Culex quinquefasciatus (southern house mosquito) emerges as temperatures rise. Spring rains create new breeding habitat. Biting pressure noticeable on warm afternoons.
What to do: Source elimination sweep — check every container in the yard. Verify CO₂ tank is full and trap is running continuously. Consider barrier treatment if hosting outdoor events.
May: Peak Season Begins
Status: High What’s happening: Multiple species active simultaneously. Tiger mosquitoes bite from sunrise to sunset. House mosquitoes active at dawn and dusk. West Nile season begins.
What to do: Both species are now active. Ensure CO₂ trap is placed optimally — near vegetation, upwind of seating areas. Evening events require additional protection (fans, barrier treatment).
June–September: Peak Season
Status: Very High What’s happening: Maximum mosquito pressure. Daily temperatures above 90°F accelerate the larval development cycle from 7 days to 4–5 days, dramatically increasing population growth rate. This is when Austin residents notice the most biting pressure.
Weather to watch: Heavy rains (June storms, August-September tropical moisture) create burst population growth 7–10 days after standing water accumulates. Drought reduces breeding but concentrates remaining mosquitoes around surviving water sources.
What to do: Continuous CO₂ trapping is essential. Tank should be checked and not allowed to run empty — even 3–5 days of downtime partially resets the suppression effect. Monthly CO₂ delivery service ensures continuity.
October: Declining but Still Active
Status: Moderate What’s happening: Tiger mosquitoes begin laying overwintering eggs as temperatures drop. Adults remain active until first frost. House mosquitoes continue until early November.
What to do: Keep the trap running through October — stopping too early allows the population to rebound before the season ends. This is also when many people get complacent and end up bitten in late October.
November: Late Season
Status: Low to Moderate What’s happening: First hard frost (typically mid-November in Austin) kills adult mosquitoes. However, Austin averages fewer than 20 hard frost days per year, and warm fronts in October–November can keep mosquitoes active well past Halloween.
What to do: Keep trap running until consistent overnight temps below 45°F. Tiger mosquito eggs are now in the soil — they’ll hatch in February.
December: Off Season
Status: Minimal What’s happening: True off season. Adult mosquitoes dead or dormant. Eggs overwintering.
What to do: Nothing required. End-of-season maintenance: clean trap mesh, store attractant in a cool place.
2026–2027 Season Forecast
Based on NOAA Climate Outlook and Austin-area historical patterns:
2026 season outlook (updated June 2026):
- La Niña conditions ended; ENSO-neutral expected through fall
- Above-normal temperatures expected May–September
- Normal to slightly below-normal precipitation June–August
- Implication: Hot and slightly dry summer = concentrated mosquitoes around remaining water sources, elevated nuisance in yards with irrigation. Slightly lower total mosquito density than a wet year, but more aggressive biting near surviving breeding sites.
When to expect peak pressure (2026): Late May → September 15
When to Install Your Trap
The answer is: before you’re miserable.
Most Austin homeowners wait until they’ve already had several unpleasant weeks on their patio before calling us. By then, the local population has built through 2–3 breeding cycles and the CO₂ trap takes longer to show results.
Ideal install: mid-March to April 1 Acceptable install: through May Late but better than nothing: through July
Book a free property assessment — we’ll assess your property’s specific mosquito pressure based on your water features, vegetation, and neighborhood and give you an accurate forecast for your yard. Same-week appointments available.