The short version
Around San Mateo, mosquito season runs from about March into November. 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.
Anyone in San Mateo tired of mosquito bites at home.
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.
- 1Wriggling larvae in birdbaths, buckets, or saucers.
- 2Dogs testing positive for heartworm.
- 3Welts on ankles and calves after yardwork.
- 4A sump pit or crawl space holding water.
- 5Kiddie pools left full for days.
- 6Bites getting worse after each wet spell.
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)
A good job starts with a walk of the whole yard. The tech looks for water that sits for days. Gutters, plant saucers, tarps, and low spots get checked first.
- Time
- 30–60 minutes
- Best for
- Every yard; finds where mosquitoes actually breed
Barrier (Residual) Yard Treatment
$75–$200 per visit; $350–$900 per season
Barrier spray is the workhorse of mosquito control in San Mateo, but it is only as good as the coverage of vegetation. Open lawns hold few adults; hedges and ivy hold thousands.
- Time
- 20–45 minutes per visit, repeated every 3–4 weeks
- Best for
- Shaded yards with shrubs, ivy, and dense landscaping
Misting Systems and In2Care-Style Stations
misting $2,000–$4,500 installed plus refills; stations $200–$500 per season
Neither option replaces the basics. Anyone in San Mateo who suggests stations or misting should still be tipping containers and treating standing water on 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
Between visits in San Mateo, a good pro uses traps or landing counts to check the treatment is still working. Numbers climbing early means a missed breeding site.
- Time
- 15–30 minutes per check; season runs spring through first frost
- Best for
- Anyone who wants the yard usable all summer
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 San Mateo.
House mosquitoes (Culex) bite from dusk into the night. They breed in storm drains. They're the main West Nile carriers. Near the coast, salt-marsh mosquitoes can fly into San Mateo from miles away. Asian tiger mosquitoes are common around San Mateo. They're black-and-white and bite by day. They breed in small containers.
Local mosquitoes conditions in San Mateo.
An inspection in San Mateo usually starts outside and works inward, checking the foundation, gaps around doors and windows, and any moisture or clutter near the structure first. Knowing San Mateo'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 San Mateo and California 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. San Mateo sits in a mediterranean climate, and that sets the pace for mosquito activity here: late spring through early fall; year-round in the deep south. For San Mateo homes, 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.
Mosquitoes that bite indoors usually slip in through gaps around doors or torn window screens.Mosquito season in San Mateo.
Plan on regular visits. West Nile cases usually peak in late summer. That's a long season.
A year of mosquitoes in San Mateo.
- Summer: with highs near 78°F in San Mateo, check water twice a week. - Fall: numbers stay high. Keep gutters clear of leaves. - Winter: a good time to fix drainage and low spots. - Spring: the first wave arrives early in San Mateo. Start treatments then.
The weekly water walk.
- 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. - Gutters: clear leaves so water drains.
Avoiding bites.
- 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. - Repellent: DEET, picaridin, IR3535 or oil of lemon eucalyptus.
Low-cost ways to cut mosquitoes.
- 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 dunks: Bti tablets kill larvae in rain barrels and ponds.
Mosquito or look-alike?
- 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. - Crane flies: look like giant mosquitoes. They don’t bite.
When a bite needs a doctor.
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. Most bites just itch for a few days. Most people infected with West Nile virus never feel sick.
Protecting your pets.
Ask your vet about year-round heartworm prevention. Change pet water bowls daily. Keep pets inside while a yard spray dries. Dogs get heartworm from mosquito bites. Cats can too.
What a treatment visit looks like.
Larvicide goes in water you can't drain. Then they spray shady shrubs, where adults rest. Most plans repeat every three to four weeks. A visit usually takes 20 to 45 minutes. The tech walks the yard first. They dump or treat standing water.
Rain barrels and ponds.
- 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. - Barrels: cover openings with fine mesh.
Questions to ask before you sign.
- 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? - What product will you spray?
What affects the price
- Commercial or multi-unit property.
- Re-treatment policy between scheduled visits.
- Special-event timing and rush scheduling.
- In2Care-style station count and servicing.
- Amount of shade and dense vegetation.
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What's your biggest concern about mosquitoes?
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
A pro adds larvicide for water you can't drain. They also spray where adults rest, every few weeks. The biggest win is free: dump standing water every week. Use repellent and run a fan on the patio.
Mosquitoes in San Mateo
San Mateo only gets about 21 inches of rain a year, so local mosquitoes breed where people add water: sprinklers, pools, fountains and AC drips. Summer highs around 78°F in San Mateo speed up the life cycle, and average humidity near 73% keeps adults active. In denser parts of San Mateo, storm drains, catch basins and gutters are big breeding spots. For San Mateo homes, the mediterranean climate means mosquitoes activity tends to follow late spring through early fall; year-round in the deep south. For San Mateo homes, 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 San Mateo, CA: what the public record shows
Before you compare quotes, it helps to know which mosquitoes actually live in California, when they are busiest around San Mateo, 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.
CDCMosquito species recorded in California
- Yellow fever mosquito (Aedes aegypti) — CDC lists Aedes aegypti as more likely than Ae. albopictus to spread dengue, Zika, and chikungunya; prefers human hosts and lives in and around homes. Tropical, subtropical, and…
When mosquitoes are busiest around San Mateo
Washington DOH: detections from May (earliest) to October (latest). California reports its heaviest WNV activity in late summer; CDC peak is late August to early September.
CDC lists California among states with limited local dengue spread from Aedes aegypti.
Rules that apply in California
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; California Department of Public Health / MVCAC; Potential Range of Aedes Mosquitoes. Figures are quoted as the source prints them. How we check our sources
Simple ways to keep mosquitoes away
- Add fish or a pump to ornamental ponds.
- Empty plant saucers after every rain.
- Check AC drip lines and sump pits.
- Replace corrugated downspout extensions with smooth pipe.
- Keep tarps taut so they shed water.
- Clean gutters each spring and fall.
Jot down where you found standing water and when you get bitten. It gives a pro a head start.Did you know?
Some species' eggs survive dry for months
Larvae are called wrigglers; pupae are tumblers
Questions people ask
What is the difference between larvicide and barrier spray?
It stops larvae from maturing. Barrier spray goes on leaves where adults rest. Most plans use both.
How do I choose a mosquito control company?
Check that they're licensed in California. Ask what products they use and how often they visit. Ask what happens if bites come back.
Will mosquito treatment kill bees and butterflies?
It can if spray hits flowers. Ask them to skip blooming plants. Spraying when bees rest helps too.
What if the mosquitoes are coming from my neighbor's property?
That's common. Treat your own yard and talk to your neighbor. Your local mosquito control district or health department can also help.
Can I get rid of mosquitoes permanently?
Not completely. They fly in from nearby. Removing water and spraying resting spots cuts them down a lot.
How likely are homeowners to hire a mosquito control service?
For San Mateo homes, mosquito control works by removing standing water, treating the water that cannot be drained, and applying barrier treatments where adults rest. For San Mateo homes, because they keep breeding through the season, an ongoing plan usually works best.
When is mosquito season in San Mateo?
It runs from about March into November. Daytime biters are tiger mosquitoes; evening biters are usually house mosquitoes.
Do mosquitoes in San Mateo carry West Nile?
They can. West Nile is found in every lower-48 state, California included. Cases usually peak in late summer. Repellent and dumping standing water are your best protection.
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Sources (11)
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