The short version
Around Washington, mosquito season runs from about May through September. Start by dumping standing water every week. A barrier spray every few weeks adds steady relief.
- Dump standing water every week.
- Daytime biters are usually tiger mosquitoes.
- Barrier sprays last about three to four weeks.
- Larvicide handles water you can’t drain.
- Use repellent with DEET, picaridin or IR3535.
Homeowners and renters in Washington who want their yard back.
What to look for
In summer heat, eggs become biting adults in about a week. Often the source is a neighbor's yard or a storm drain. Mosquitoes breed in standing water, even a bottle cap's worth.
- 1Corrugated downspout extensions that never drain.
- 2Egg rafts floating on stagnant water.
- 3Rain barrels without screens or lids.
- 4Whining near your ears at night indoors.
- 5Bites getting worse after each wet spell.
- 6Welts on ankles and calves after yardwork.
Why it’s worth acting soon
- Each new generation is bigger than the last.
- Bites can spread West Nile virus.
- Itchy welts, especially for kids.
- Heartworm risk for dogs.
bite, to get protein for their eggsOnly female mosquitoesUS CDC in standing water, from a bottle cap to a pondMosquitoes breedUS EPA West Nile virus is the most common mosquito-borne disease in the U.S.Mosquito diseasesUS CDC Treatment options and typical costs
Property Inspection for Breeding Sites
$0–$150 (often bundled with a first treatment)
Most mosquitoes biting you in Washington were born within a few hundred feet of your door, so the inspection maps every container, drain, and puddle on the lot. That map becomes the treatment plan.
- Time
- 30–60 minutes
- Best for
- Every yard; finds where mosquitoes actually breed
Misting Systems and In2Care-Style Stations
misting $2,000–$4,500 installed plus refills; stations $200–$500 per season
Neither option replaces the basics. A pro should still dump and treat standing water every visit.
- Time
- Misting: half a day. Stations: under an hour.
- Best for
- Specific yards: heavy outdoor use or spray-averse owners
Monitoring and Seasonal Plans
$50–$150 per follow-up visit; $350–$900 per season bundled
Ask your pro what happens if bites come back between visits. Many plans include a re-spray within a set window. Ask first.
- Time
- 15–30 minutes per check; season runs spring through first frost
- Best for
- Anyone who wants the yard usable all summer
Source Reduction and Larviciding
$75–$150 per visit
Because larvicide works on mosquitoes that can't fly away yet, it's the foundation of most plans in Washington. Adult spraying is the follow-up, not the fix.
- Time
- 45–90 minutes
- Best for
- Yards with standing water, clogged gutters, ponds, or drains
Prices are typical published ranges. Ask what’s included before you compare quotes.
Leaf-clogged gutters and downspouts hold water out of sight. Clearing them in fall means fewer places to breed in spring.Which mosquitoes bite around Washington.
Asian tiger mosquitoes are common around Washington. They're black-and-white and bite by day. They breed in small containers. House mosquitoes (Culex) bite from dusk into the night. They breed in storm drains. They're the main West Nile carriers.
Local mosquitoes conditions in Washington.
Washington sits in a humid subtropical climate, and that sets the pace for mosquito activity here: late spring through early fall; year-round in the deep south. In Washington, the area is mostly urban, so mosquitoes pressure can differ from one block to the next depending on how tight the entry points are and how much food, water, or shelter is close by. An inspection in Washington usually starts outside and works inward, checking the foundation, gaps around doors and windows, and any moisture or clutter near the structure first. Knowing Washington's seasonal timing lets you schedule treatment before the busy stretch rather than after it, which usually means faster service and a more accurate quote. A provider who works Washington and District of Columbia every day can point out the specific conditions that matter most here, and getting the scope, price, and follow-up terms in writing makes it easier to compare options.
Mosquitoes that bite indoors usually slip in through gaps around doors or torn window screens.Mosquito season in Washington.
Numbers usually peak in July and August. West Nile cases usually peak in late summer.
A year of mosquitoes in Washington.
- Spring: dump water and clean gutters before May. - Summer: peak season in Washington, especially July and August. - Fall: activity fades with cooler nights. - Winter: fix drainage and store containers upside down.
The weekly water walk.
- Gutters: clear leaves so water drains. - Saucers and pots: empty them or add sand. - Toys and buckets: store them upside down. - Tarps and covers: pull them tight so water runs off. - Birdbaths: change the water twice a week. - Pet bowls: refresh daily. - AC drip lines and downspouts: make sure water drains away. - Tree holes: fill them with sand.
Avoiding bites.
- Repellent: DEET, picaridin, IR3535 or oil of lemon eucalyptus. - Clothing: long sleeves and pants help at dusk. - Fans: a patio fan keeps weak-flying mosquitoes away. - Screens: repair holes in window and door screens. - Timing: tiger mosquitoes bite by day; house mosquitoes at dusk.
Low-cost ways to cut mosquitoes.
- Mosquito dunks: Bti tablets kill larvae in rain barrels and ponds. - Mosquito fish: they eat larvae in ornamental ponds. - Pumps and fountains: moving water breeds far fewer mosquitoes. - Trimming: thin out dense shrubs and tall grass. - Lights: yellow bug lights attract fewer insects to the porch.
Mosquito or look-alike?
- Crane flies: look like giant mosquitoes. They don’t bite. - Non-biting midges: swarm near water at dusk. Harmless, just annoying. - No-see-ums: tiny biting gnats near marshes. Screens need a finer mesh. - Mosquitoes: slim, long legs, and a needle-like mouth.
When a bite needs a doctor.
Most bites just itch for a few days. Most people infected with West Nile virus never feel sick. About one in five get a fever, headache or body aches. See a doctor for high fever, stiff neck or confusion. Spreading swelling or an infected-looking bite needs a check too.
Protecting your pets.
Dogs get heartworm from mosquito bites. Cats can too. Ask your vet about year-round heartworm prevention. Change pet water bowls daily. Keep pets inside while a yard spray dries.
What a treatment visit looks like.
A visit usually takes 20 to 45 minutes. The tech walks the yard first. They dump or treat standing water. Larvicide goes in water you can't drain. Then they spray shady shrubs, where adults rest. Most plans repeat every three to four weeks.
Rain barrels and ponds.
- Barrels: cover openings with fine mesh. - Ponds: fish and moving water keep larvae down. - Bird baths: change the water every few days. - Gutters: clear them so water drains away. - Tarps: shake out any that hold rainwater. - Pool covers: drain standing water after rain.
Questions to ask before you sign.
- What product will you spray? - How often will you come? - Do you treat standing water too? - What happens if bites come back between visits? - How do you protect bees and flowers? - When can kids and pets go back outside?
Why mosquito problems come back after you treat.
Mosquitoes breed in standing water, and new adults keep emerging as long as that water is there. A barrier spray kills the adults that are flying, but it does not stop the next generation. That is why the most effective control starts with removing or treating the water, then adding larvicide and barrier treatments for the adults.
Source reduction is the cheapest control.
Emptying the water mosquitoes use is free and does more than any product — gutters, buckets, saucers, toys, tarps, and anything else that holds water for a week. Treat the water that cannot be drained, and the breeding stops. A yard with no standing water is a yard mosquitoes mostly pass over.
What affects the price
- Special-event timing and rush scheduling.
- Commercial or multi-unit property.
- One-time visit versus a seasonal plan.
- Lot size and total acreage treated.
- Amount of shade and dense vegetation.
📊
What is your biggest challenge with mosquitoes in your yard?
When to call for help
Call if bites still keep you indoors. Dumping water should come first. early in the season, before the first big wave. Ponds, drains and dense shrubs are hard to handle yourself.
What you can do yourself
The biggest win is free: dump standing water every week. Use repellent and run a fan on the patio. A pro adds larvicide for water you can't drain. They also spray where adults rest, every few weeks.
Mosquitoes in Washington
With about 40 inches of rain a year in Washington, any container left out will hold water within days. Summer highs around 89°F in Washington speed up the life cycle, and average humidity near 66% keeps adults active. In denser parts of Washington, storm drains, catch basins and gutters are big breeding spots. In Washington, the humid subtropical climate means mosquitoes activity tends to follow late spring through early fall; year-round in the deep south. In Washington, that timing is worth keeping in mind when you schedule a visit, because treating before the busy stretch is usually cheaper and simpler than chasing a full-blown problem later, and it leaves you more time to compare providers and their written quotes.
Local research
Mosquitoes in Washington, DC: what the public record shows
Before you compare quotes, it helps to know which mosquitoes actually live in District of Columbia, when they are busiest around Washington, and what the state figures look like. Everything below links to the agency or university page it came from.
West Nile neuroinvasive disease cases, 2024
Neuroinvasive counts are the most reliable state comparison because nearly all severe cases are diagnosed and reported.
CDCWhen mosquitoes are busiest around Washington
CDC: West Nile transmission June through October, peaking late August to early September. Illinois found its first positive mosquito batch of 2025 on May 9, so larval control should start in May.
For context, nationally
- 1,808 — West Nile virus disease cases reported, 2024. CDC
- 1,347 (75% of cases); 173 deaths — West Nile neuroinvasive disease cases, 2024. CDC
Sources: CDC. Figures are quoted as the source prints them. How we check our sources
Simple ways to keep mosquitoes away
- Wear DEET or picaridin repellent outdoors.
- Book barrier treatments before the season starts.
- Trim shrubs and ivy to reduce resting cover.
- Keep tarps taut so they shed water.
- Clean gutters each spring and fall.
- Drop Bti dunks in water you cannot drain.
Renting? Shared courtyards, drains and landscaping are usually the property manager's to handle, so let them know.Did you know?
A female's wings beat hundreds of times per second
Mosquito means little fly in Spanish
Questions people ask
Why are there so many mosquitoes in my yard specifically?
Usually there's water nearby, like a clogged gutter or tarp. Shady, damp plants give them a place to rest.
Are misting systems worth it?
For a few homes, yes. They're costly to install and need refills. Most yards do fine with source removal and regular spraying.
What should I do before the pro arrives?
Dump standing water. Move toys and pet bowls. Tell them where you get bitten most.
When should mosquito treatments start each year?
Before the first big wave. Around Washington, the season runs from about May through September, so start a few weeks before.
How long does a mosquito treatment last?
A barrier spray usually lasts three to four weeks. Heavy rain can shorten that.
When is mosquito season in Washington?
It runs from about May through September. Daytime biters are tiger mosquitoes; evening biters are usually house mosquitoes.
Do mosquitoes in Washington carry West Nile?
They can. West Nile is found in every lower-48 state, District of Columbia included. Cases usually peak in late summer. Repellent and dumping standing water are your best protection.
Sources (10)
The facts in this article come from the public sources listed above. Every home is different, so ask the company you talk to about pricing and what’s included. Published by Mosquito Exterminator · Updated September 11, 2026 · How we write these guides