What time of year are fleas worst?

Fleas are worst during warm, humid months, typically late spring through summer and early fall, from May to September in many regions, though they can be active year round indoors in heated homes and in warm climates. Fleas thrive in temperatures of 70 to 85 degrees Fahrenheit and humidity of 70 percent or higher, conditions common in summer, which accelerate their life cycle from egg to adult to as short as 3 weeks, leading to rapid population growth from few fleas to hundreds. In summer, pets spend more time outdoors in tall grass, shaded moist areas, and near wildlife like raccoons and squirrels that carry fleas, increasing exposure and bringing fleas indoors where eggs fall off into carpets and pet bedding. Flea pupae that have remained dormant for months in cocoons waiting for vibrations and warmth emerge in summer when hosts are active. In cooler months, flea development slows but does not stop indoors, as heated homes provide warmth and pets provide blood meals, so infestations can persist year round. Peak flea season also coincides with increased flea allergy dermatitis in pets. To prevent worst infestations, treat pets year round with veterinarian approved flea preventative, wash pet bedding weekly in hot water and dry on high heat, vacuum thoroughly, and treat yard by mowing and removing debris, starting prevention in early spring before peak season.