The short version
Around San Diego, mosquito season runs from about March into November. Treatment means removing water and treating what you can't drain. A barrier spray follows every few weeks.
- 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 San Diego who want their yard back.
What to look for
Often the source is a neighbor's yard or a storm drain. In summer heat, eggs become biting adults in about a week. Mosquitoes breed in standing water, even a bottle cap's worth.
- 1Dogs testing positive for heartworm.
- 2Whining near your ears at night indoors.
- 3Bites getting worse after each wet spell.
- 4Standing water in low spots a week after rain.
- 5Swarms rising from shrubs when you brush past.
- 6Egg rafts floating on stagnant water.
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.
📅
Mosquito activity through the year in San Diego
Spring
the first wave arrives early in San Diego. Start treatments then.
Summer
with highs near 76°F in San Diego, check water twice a week.
Fall
numbers stay high. Keep gutters clear of leaves.
Winter
a good time to fix drainage and low spots.
Treatment options and typical costs
Property Inspection for Breeding Sites
$0–$150 (often bundled with a first treatment)
Resting spots get a look as well: thick shrubs, ivy, the space under decks and shady fence lines around your San Diego home. Knowing where adults hide shows where barrier spray matters.
- 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
For a San Diego yard that hosts a lot of outdoor living, a fixed misting system releases insecticide from nozzles on a timer. It is the highest-cost option and needs regular refills.
- 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
A good pro checks landing counts between visits. 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
Source Reduction and Larviciding
$75–$150 per visit
Expect some tips on this visit too, since you can clear most breeding sites on a San Diego lot yourself. A pro points them out so they stay gone.
- 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.
A treatment visit covers the shaded plants and beds where adults rest, along with any standing water that can't be drained.How mosquito treatment works in San Diego.
Barrier spray covers shady shrubs and leaves. Larvicide handles water you can't drain, like ponds or drains. Around San Diego, the season runs from about March into November, so a plan usually starts in spring and runs to the end of the season. Then spray where the adults rest. First, find and remove the water where they breed. Treatment has two parts.
Which mosquitoes bite around San Diego.
Near the coast, salt-marsh mosquitoes can fly into San Diego from miles away. They're the main West Nile carriers. They breed in storm drains. House mosquitoes (Culex) bite from dusk into the night. They also bite by day, often near or inside homes. Yellow fever mosquitoes live around San Diego too. They breed in small containers. They're black-and-white and bite by day. Asian tiger mosquitoes are common around San Diego.
Mosquitoes that bite indoors usually slip in through gaps around doors or torn window screens.Mosquito season in San Diego.
West Nile cases usually peak in late summer. Plan on regular visits. That's a long season.
A year of mosquitoes in San Diego.
- Winter: a good time to fix drainage and low spots. - Fall: numbers stay high. Keep gutters clear of leaves. - Summer: with highs near 76°F in San Diego, check water twice a week. - Spring: the first wave arrives early in San Diego. Start treatments then.
The weekly water walk.
- Tree holes: fill them with sand. - AC drip lines and downspouts: make sure water drains away. - Pet bowls: refresh daily. - Birdbaths: change the water twice a week. - Tarps and covers: pull them tight so water runs off. - Toys and buckets: store them upside down. - Saucers and pots: empty them or add sand. - Gutters: clear leaves so water drains.
Avoiding bites.
- Timing: tiger mosquitoes bite by day; house mosquitoes at dusk. - Screens: repair holes in window and door screens. - Fans: a patio fan keeps weak-flying mosquitoes away. - Clothing: long sleeves and pants help at dusk. - Repellent: DEET, picaridin, IR3535 or oil of lemon eucalyptus.
Low-cost ways to cut mosquitoes.
- Lights: yellow bug lights attract fewer insects to the porch. - Trimming: thin out dense shrubs and tall grass. - Pumps and fountains: moving water breeds far fewer mosquitoes. - Mosquito fish: they eat larvae in ornamental ponds. - Mosquito dunks: Bti tablets kill larvae in rain barrels and ponds.
Mosquito or look-alike?
- Mosquitoes: slim, long legs, and a needle-like mouth. - No-see-ums: tiny biting gnats near marshes. Screens need a finer mesh. - Non-biting midges: swarm near water at dusk. Harmless, just annoying. - Crane flies: look like giant mosquitoes. They don’t bite.
When a bite needs a doctor.
Spreading swelling or an infected-looking bite needs a check too. See a doctor for high fever, stiff neck or confusion. About one in five get a fever, headache or body aches. Most people infected with West Nile virus never feel sick. Most bites just itch for a few days.
Protecting your pets.
Refresh pet water bowls daily; in dry San Diego a bowl or an irrigation puddle is often the only standing water on the block. Keep animals inside until a yard treatment dries. Talk to your vet about year-round prevention. Heartworm reaches dogs through mosquito bites, and cats can get it as well; San Diego's June–October season is long enough that most vets advise year-round prevention.
What a treatment visit looks like.
Most plans repeat every three to four weeks. Then they spray shady shrubs, where adults rest. Larvicide goes in water you can't drain. They dump or treat standing water. The tech walks the yard first. A visit usually takes 20 to 45 minutes.
Rain barrels and ponds.
- Pool covers: drain standing water after rain. - Tarps: shake out any that hold rainwater. - Gutters: clear them so water drains away. - Bird baths: change the water every few days. - Ponds: fish and moving water keep larvae down. - Barrels: cover openings with fine mesh.
Questions to ask before you sign.
- When can kids and pets go back outside? - How do you protect bees and flowers? - What happens if bites come back between visits? - Do you treat standing water too? - How often will you come? - What product will you spray?
What affects the price
- Standing water requiring larvicide.
- Special-event timing and rush scheduling.
- Re-treatment policy between scheduled visits.
- Lot size and total acreage treated.
- Misting system installation and refills.
- Ponds, creeks, or wetland edges on the property.
📊
What's your biggest concern about mosquitoes?
When to call for help
Ponds, drains and dense shrubs are hard to handle yourself. early in the season, before the first big wave. Dumping water should come first. Call if bites still keep you indoors.
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 San Diego
San Diego only gets about 10 inches of rain a year, so local mosquitoes breed where people add water: sprinklers, pools, fountains and AC drips. Summer highs around 76°F in San Diego speed up the life cycle, and average humidity near 69% keeps adults active. In denser parts of San Diego, storm drains, catch basins and gutters are big breeding spots. San Diego has a mediterranean climate, and mosquitoes activity here tends to pick up late spring through early fall; year-round in the deep south. Around San Diego, most of the housing is urban, so the usual entry points, moisture spots, and sheltered areas near the structure are what an inspection checks first. Around San Diego, take a minute to note where you have seen activity and when it appears, so the inspection is faster and the quote more accurate. A local provider who knows San Diego and California can point out the specific conditions that matter most here before you commit to a plan.
Local research
Mosquitoes in San Diego, 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 Diego, 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 Diego
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
- Wear DEET or picaridin repellent outdoors.
- Add fish or a pump to ornamental ponds.
- Clean gutters each spring and fall.
- Cover or drill drainage holes in tires.
- Run a fan on the patio at dusk.
- Store buckets, wheelbarrows, and toys upside down.
Jot down where you found standing water and when you get bitten. It gives a pro a head start.Did you know?
A female's wings beat hundreds of times per second
Some species' eggs survive dry for months
Questions people ask
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.
Do I need a seasonal plan or is one treatment enough?
One treatment helps for an event or a few weeks. Barrier sprays fade in three to four weeks. Steady relief takes repeat visits.
Can mosquito control help with West Nile risk?
It can lower it by cutting the number of biting mosquitoes. Repellent and dumping standing water still matter most.
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.
When should mosquito treatments start each year?
Before the first big wave. Around San Diego, the season runs from about March into November, so start a few weeks before.
Do store-bought mosquito products actually work?
Around San Diego, dIY sprays and foggers give temporary relief, but they do not stop the next generation from breeding in the standing water nearby. Around San Diego, the most effective DIY step is removing the water, and professional larvicide and barrier treatments handle the rest.
When is mosquito season in San Diego?
It runs from about March into November. Daytime biters are tiger mosquitoes; evening biters are usually house mosquitoes.
Do mosquitoes in San Diego 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.
Nearby cities
Related guides
Sources (16)
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