The Best and Worst Times of the Day for Mosquito Activity

The worst time of day for mosquitoes is dusk and the first few hours of darkness, with a second, smaller peak around dawn. That is when most species, including the house mosquitoes that carry West Nile virus, come out to feed. There is one big exception in Oklahoma: the Asian tiger mosquito, the black-and-white striped mosquito that is the most common biter in our towns, is most active in mid to late afternoon. The best time to be outside is the middle of a hot, sunny, breezy day, out in the open and away from shade and standing water.

Mosquito activity by time of day

Why different mosquitoes bite at different times

Daytime biters: Asian tiger and yellow fever mosquitoes

These two Aedes mosquitoes are black with white stripes and breed in small containers around homes. OSU entomologists call the Asian tiger mosquito the most important pest mosquito in most urban areas of Oklahoma from early June through fall, and note it is most active in mid to late afternoon. That is why evening fogging often misses it. The CDC says these mosquitoes fly only a few blocks in their lifetime, so if you are getting bitten on your patio at 4 p.m., they were likely raised in your yard or a neighbor's.

Dusk-to-dawn biters: house mosquitoes

House mosquitoes (Culex) are plain brown and breed in foul water such as storm drains, ditches and clogged gutters. The CDC says they are most active from dusk to dawn and rest during the day in grass, shrubs and thick vegetation. These are the main carriers of West Nile virus in Oklahoma, which is why the Oklahoma State Department of Health stresses repellent "especially between dusk and dawn."

Evening and shade biters: floodwater mosquitoes

After heavy rain, floodwater mosquitoes hatch in huge numbers. OSU notes that the species active after spring flooding typically bite in the evening or when disturbed in shady areas, so mowing, gardening or walking through tall grass can set off a swarm even in daylight.

Are mosquitoes active at night?

Yes. Many people assume mosquitoes disappear after sunset, but house mosquitoes are just getting started. They feed through the night, and activity only drops off when the air cools. A mosquito that gets indoors is the worst case: inside, it is sheltered from heat and wind, and a sleeping person is an easy target. OSU notes that the common malaria mosquito often comes indoors to feed at night. Keep screens repaired, run the air conditioning, and close doors quickly in the evening.

When are mosquitoes least active?

• Midday heat and sun. Most mosquitoes avoid hot, dry, sunny air and rest in shade until evening.
• Wind. Mosquitoes are weak fliers. A breezy day, or a strong fan on the patio, keeps many of them grounded.
• Cool weather. Activity drops sharply on cold nights and in late fall, and a hard freeze ends the season.
• Dry spells. Fewer breeding sites mean fewer mosquitoes, though they crowd around any water that remains.

The exception to the midday rule is shade. Walk under trees, into tall grass or onto a covered deck at noon and you can still get bitten, especially by tiger mosquitoes.

The worst times of year

In Oklahoma, the worst stretch is mid to late summer. Asian tiger mosquitoes are a daytime pest from early June through fall, and the Culex mosquitoes that carry West Nile virus become more abundant in mid to late summer, when it is hot and dry (OSDH). Rain matters as much as the calendar: University of Illinois Extension notes that big hatches of biting mosquitoes typically follow heavy rain by about two weeks. Activity slows in fall and usually ends with the first hard freeze. See the Oklahoma mosquito ID guide for the full season.

Where mosquitoes are worst

• Near standing water: ponds with weedy edges, ditches, low spots that flood, storm drains and neglected pools.
• Anywhere containers hold water: buckets, flower pot saucers, tires, toys, tarps, birdbaths and clogged gutters.
• In dense shade: shrubs, tall grass, ivy and groundcover, wooded lot edges and under decks.
• Out of the wind: fenced, sheltered patios and screened areas with gaps.

How to plan around mosquitoes

1. Put on repellent before dusk. Use an EPA-registered product with DEET, picaridin, IR3535, oil of lemon eucalyptus, PMD or 2-undecanone (CDC). OSU suggests reapplying about an hour before dusk if you will be working outside into the night.
2. Cover up in the afternoon too if tiger mosquitoes are biting, not just at dusk.
3. Wear loose, long sleeves and pants. OSU notes tiger mosquitoes can bite through thin fabric, so treat clothing with permethrin, never skin.
4. Run a fan on the patio or porch.
5. Mow and trim shrubs and tall grass where mosquitoes rest.
6. Dump standing water at least once a week. It is the only way to cut the population at the source. Our mosquito prevention guide has a checklist.

How Emtec treats mosquitoes

You cannot plan every evening around mosquitoes. Our mosquito treatment pairs an adulticide, which kills adult mosquitoes, with an insect growth regulator, which stops eggs and young mosquitoes from developing. Technicians apply it with a backpack mister to the shrubs, foliage and shady spots where mosquitoes rest, including the undersides of leaves and the space under decks. Treating the resting spots is what reaches the daytime tiger mosquitoes as well as the night biters.

Mosquito exterminator in Tulsa and Oklahoma City

If dusk on your patio has turned into a swatting match, a mosquito exterminator can help you take it back. Emtec Pest Control has served Oklahoma homes since 1979. We serve Tulsa, Broken Arrow, Owasso, Jenks, Bixby, Sand Springs, Sapulpa, Stillwater, Oklahoma City, Edmond and nearby towns. Learn about our mosquito control service, see how to keep the rest of your yard bug-free in keeping your patio and deck pest-free, or contact us.