The short version
Around Fort Collins, mosquito season runs from about May through September. Treatment means removing water and treating what you can't drain. A barrier spray follows every few weeks.
- Dump standing water every week.
- Evening biters are usually house 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 Fort Collins tired of mosquito bites at home.
What to look for
Mosquitoes breed in standing water, even a bottle cap's worth. In summer heat, eggs become biting adults in about a week. Often the source is a neighbor's yard or a storm drain.
- 1Tarps, toys, or tires holding rainwater.
- 2Kiddie pools left full for days.
- 3Swarms rising from shrubs when you brush past.
- 4Adults resting under deck boards or in ivy.
- 5Standing water in low spots a week after rain.
- 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 📅
Mosquito activity through the year in Fort Collins
Spring
dump water and clean gutters before May.
Summer
peak season in Fort Collins, especially July and August.
Fall
activity fades with cooler nights.
Winter
fix drainage and store containers upside down.
Treatment options and typical costs
Property Inspection for Breeding Sites
$0–$150 (often bundled with a first treatment)
In Fort Collins, a good inspection sets expectations too: a yard that backs onto a wetland won't respond like a dry cul-de-sac, and the pro should tell you that up front.
- 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 Fort Collins 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
Barrier (Residual) Yard Treatment
$75–$200 per visit; $350–$900 per season
Barrier spray is the workhorse of mosquito control in Fort Collins, 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
Source Reduction and Larviciding
$75–$150 per visit
Expect some tips on this visit too, since you can clear most breeding sites on a Fort Collins 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.
Adult mosquitoes spend the day in shady, leafy beds like this one, so that's where a barrier treatment goes.How mosquito treatment works in Fort Collins.
Treatment has two parts. First, find and remove the water where they breed. Then spray where the adults rest. In Fort Collins, the season runs from about May through September, so a plan usually starts in spring and runs to the end of the season. Larvicide handles water you can't drain, like ponds or drains. Barrier spray covers shady shrubs and leaves.
Which mosquitoes bite around Fort Collins.
House mosquitoes (Culex) bite from dusk into the night. They breed in storm drains. They're the main West Nile carriers. Floodwater mosquitoes hatch in big waves after heavy rain or snowmelt. They can travel a long way from where they hatch.
Mosquitoes that bite indoors usually slip in through gaps around doors or torn window screens.Mosquito season in Fort Collins.
Numbers usually peak in July and August. West Nile cases usually peak in late summer.
A year of mosquitoes in Fort Collins.
- Spring: dump water and clean gutters before May. - Summer: peak season in Fort Collins, 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?
What affects the price
- Standing water requiring larvicide.
- Synthetic versus botanical barrier products.
- Lot size and total acreage treated.
- Special-event timing and rush scheduling.
- Misting system installation and refills.
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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
They also spray where adults rest, every few weeks. A pro adds larvicide for water you can't drain. Use repellent and run a fan on the patio. The biggest win is free: dump standing water every week.
Mosquitoes in Fort Collins
Fort Collins only gets about 16 inches of rain a year, so local mosquitoes breed where people add water: sprinklers, pools, fountains and AC drips. Summer highs around 87°F in Fort Collins speed up the life cycle. In denser parts of Fort Collins, storm drains, catch basins and gutters are big breeding spots. Fort Collins has a semi-arid climate, and mosquitoes activity here tends to pick up late spring through early fall; year-round in the deep south. In Fort Collins, 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. In Fort Collins, 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 Fort Collins and Colorado can point out the specific conditions that matter most here before you commit to a plan. In Fort Collins, before you book, ask whether the inspection is included, what the treatment plan covers, how many visits to expect, and what the written quote includes. In Fort Collins, getting the scope, the prep steps, and any follow-up terms in writing makes it much easier to compare providers fairly, and a good provider will walk you through each of these without pressure. In Fort Collins, a little preparation usually makes the visit more useful: clear access to the areas where you have seen activity, put away loose items, and note anything you have noticed recently. In Fort Collins, if you have photos or a rough timeline of when the problem started, share them, because those details help the provider confirm what is going on and give you a more accurate scope and price.
Local research
Mosquitoes in Fort Collins, CO: what the public record shows
Before you compare quotes, it helps to know which mosquitoes actually live in Colorado, when they are busiest around Fort Collins, 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 Fort Collins
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
- Clean gutters each spring and fall.
- Drop Bti dunks in water you cannot drain.
- Fix low spots that hold water for days.
- Dump and scrub birdbaths every week.
- Tighten lids on trash and recycling bins.
- Trim shrubs and ivy to reduce resting cover.
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
Larvae are called wrigglers; pupae are tumblers
Questions people ask
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.
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.
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.
What are In2Care stations and do they work?
They're small water traps. Mosquitoes visit, then carry larvicide to other water. They work best against container breeders like tiger mosquitoes.
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 is mosquito season in Fort Collins?
It runs from about May through September.
Do mosquitoes in Fort Collins carry West Nile?
They can. West Nile is found in every lower-48 state, Colorado included. Cases usually peak in late summer. Repellent and dumping standing water are your best protection.
Nearby cities
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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