Florida Mosquito Season: Month-by-Month Guide

Florida does not have a defined mosquito season with a clear start and end date the way northern states do. Mosquitoes are present and active year-round in South Florida (Broward and Palm Beach counties). The population peaks dramatically during the rainy season (May—October) when warm temperatures, daily rainfall, and increased standing water combine to accelerate breeding and adult emergence. But even in Florida's coolest months (December—February), Culex quinquefasciatus remains active, adult populations persist, and biting pressure – while lower than summer – is not zero. 'Mosquito season in Florida is every month' is the accurate description for the South Florida service area.

August and September are typically the peak months for mosquito pressure in Broward and Palm Beach counties. These months combine the cumulative effect of 3—4 months of continuous rainy season breeding, maximum temperatures that accelerate the breeding cycle, and the greatest volume of accumulated standing water from the season's rain. After major storm events in these months, floodwater species from the Everglades can migrate into residential areas in very large numbers within 24—48 hours. June is typically when rainy season begins in earnest and the first major population surge is seen.

For South Florida (Broward and Palm Beach counties), year-round service is the appropriate approach. Year-round service maintains active residual barrier protection before the rainy season begins rather than scrambling to establish control after the first summer surge. Practically, if you're starting from scratch, beginning service in March or April – before the May rainy season onset – allows 2—3 treatment visits to build up the Kill/Mask/Repel residual in your vegetation before pressure peaks. Starting at the first sign of biting (typically when you notice you're getting bitten outdoors) means you're already behind the population curve.

No – mosquitoes do not die out during Florida's winter. South Florida does not experience temperatures cold enough to kill adult mosquitoes or prevent winter breeding. Culex quinquefasciatus remains active in South Florida winters, particularly in warmer microhabitats near water. What does change in winter: adult population density is lower (less breeding pressure from reduced rainfall), peak biting hours shift (Culex may be active slightly earlier in the evening as temperatures drop), and some species are less active in genuinely cool periods (below 50°F). But 'Florida winter' in the Boca Raton/Fort Lauderdale area rarely produces sustained temperatures below 60°F, and population pressure – while reduced from summer peaks – is year-round.

South Florida's rainy season officially runs from mid-May to mid-October – approximately 5 months. During this period, South Florida receives about 70% of its annual rainfall, with daily afternoon thunderstorms as the dominant weather pattern. This sustained rainfall maintains abundant standing water throughout the region, enabling year-round breeding source availability. The effect on mosquito populations is dramatic: peak summer populations can be 10—20× the winter baseline. The combination of maximum population pressure, maximum outdoor activity (pools, patios, outdoor entertainment), and warm temperatures that keep people outdoors late in the evening makes May—October the most important window for active professional mosquito control.

Sustained temperatures below 40°F will begin to kill adult South Florida mosquitoes, but such temperatures are rare and brief in Broward and Palm Beach counties. A hard freeze (28°F or below for 4+ hours) can kill most surface-resting adults and may temporarily slow the breeding cycle by cooling standing water. However, South Florida averages fewer than 5 nights per year with temperatures below 40°F, and typically none below 35°F in the coastal communities we serve. A single cold night does not eliminate the mosquito population – eggs and larvae can survive brief cold exposure, and adults sheltering in protected microhabitats survive temperatures that kill exposed individuals. After a cold snap, populations can rebound rapidly when temperatures return to the 60s and above.