What time of day are mosquitoes worst?

What time of day mosquitoes are worst depends on species, but generally mosquitoes are worst at dusk and dawn, with peak biting activity in evening around sunset and early morning around sunrise. Many common mosquito species, especially Culex mosquitoes that transmit West Nile virus and Aedes mosquitoes that are day biters, have different peak times. Culex mosquitoes, which are nocturnal, are most active from dusk, about 7 to 10 pm, through night until dawn, with peak around 10 pm to 3 am, making evening and nighttime worst for them. Aedes aegypti and Aedes albopictus, which transmit Zika, dengue, and chikungunya, are day biters with peaks in early morning 6 to 10 am and late afternoon 4 to 7 pm, so late afternoon is worst for them. Overall, worst times for most people are dusk and dawn when temperatures cooler, humidity higher, and winds calmer, which favor mosquito flight. Midday with hot sun and low humidity is least active for most species, except shaded areas where day biters still active. Mosquitoes are attracted to carbon dioxide, body heat, and skin odors, and at dusk people are often outside for barbecues and activities, increasing exposure. To avoid worst times, stay indoors at dusk and dawn, use fans outdoors, wear long sleeves, and apply EPA-registered repellents like DEET or picaridin during peak times.