When is mosquito season in Minneapolis?

June through September, peaking in late June and July. MMCD's season starts when degree days accumulate in spring, typically May, and ends with frost in late September or October.

Why are Minnesota mosquitoes so bad after a wet spring?

Aedes vexans lays eggs on damp soil at wetland margins; they hatch when rising water covers them. A wet spring floods thousands of acres at once, and about ten days later the metro is swarmed. A dry spring, as in 2021, means a quiet summer.

Is West Nile virus a risk in Minneapolis?

Yes, mostly in late summer: Culex tarsalis carries it, and Minnesota records human cases most years, more in the west of the state. MMCD and the Minnesota Department of Health report detections; follow them over the index.

Where does this forecast's data come from?

Open-Meteo weather for downtown Minneapolis, scored by our documented model with the northern breeding lag (10–21 days), and compared with Hennepin County's season-map climatology. Not a trap count.

Mosquito forecast

Minneapolis Mosquito Forecast

Today's mosquito activity in Minneapolis, the week ahead, and what to do about it. Updated hourly.Today's mosquito activity in Minneapolis on a 0–100 Bite Index, the week ahead, and what to do about it. Built from the rain and temperature that drive Hennepin County's trap counts; updated hourly.

Bite Index · Sunday, November 8

Low

Mosquito activity in Minneapolis is low today.

Few mosquitoes. You may see one or two at dusk near water.

About normal for November in Hennepin County.

The week has averaged 48°F, below the 50°F where mosquitoes stop flying and breeding. Nothing to forecast until it warms up.

The week ahead

Each day's Bite Index, from this week's weather and the rain that is still hatching. Forecast days get less certain as the week goes on.

Today
0LowLow54°/40°dry
Mon
0LowLow54°/38°dry
Tue
0LowLow58°/36°dry
Wed
0LowLow50°/39°dry
Thu
0LowLow40°/33°dry
Fri
0LowLow41°/32°dry
Sat
0LowLow47°/33°dry

Protect tonight

You can probably skip repellent tonight.

If you're near a creek, pond or heavy shade at dusk, a light application on ankles and arms is plenty.
Good night to tip out any containers holding water; what you empty now won't hatch next week.

Which repellent, and how much: DEET vs picaridin Best natural repellents

Why Minneapolis's mosquitoes do what they do

Minneapolis is the land of ten thousand lakes and, in a wet June, uncountable mosquitoes. The Metropolitan Mosquito Control District covers the seven-county metro with trapping, larviciding of wetlands and treatment alerts, and projects each season from degree days and the previous year's rain. The season is short, but a wet spring followed by heat makes it the worst in the country for a few weeks.

Wetlands everywhere: the district treats tens of thousands of acres of wetland for floodwater Aedes vexans, the dominant nuisance species.
Degree days: cool springs delay the season; MMCD projects the start from accumulated warmth, as this index does.
Rain-driven broods: Aedes vexans hatches en masse about ten days after a soaking rain; a dry June means a quiet July.
Very short season: June through September; the index is zero from October to May.

A typical year in Hennepin County

The long-run mosquito index by month from our season map (NOAA climate normals plus effort-corrected sightings). Today's Bite Index is the live version of this; the month you're in is marked.

JJanuary: 0
FFebruary: 0
MMarch: 0
AApril: 0
MMay: 45
JJune: 68
JJuly: 75
AAugust: 69
SSeptember: 55
OOctober: 0
NNovember: 0
DDecember: 0

Local surveillance and West Nile virus

The Bite Index measures nuisance biting, not disease. Hennepin County's health department traps and tests mosquitoes through the season and publishes positive West Nile pools by ZIP code. When your ZIP has an active advisory, follow it regardless of today's number.

Metropolitan Mosquito Control District
The seven-county Twin Cities district: trap counts, treatment alerts by area, and spring season projections.

How the Bite Index is scored

The index is a model of conditions, not a mosquito count. Four weather factors are combined on a 0–100 scale, then scaled by the season. Every factor and today's value for it is listed here so you can check the number yourself. It uses the same temperature curve and rain logic as our county-level mosquito season map, which has been validated against effort-corrected sighting data across 41 states.

BBreeding pressure

Rain 7–14 days ago (0.4 in. between Oct 8 and Oct 23). Eggs need water to hatch, and at summer temperatures the egg-to-biting-adult cycle takes about a week, so today's mosquitoes are last week's rain. Cool weather stretches the window; hot dry days shrink it as shallow water evaporates.

Weight 40%

Today 15%

DDevelopment

The trailing two-week average temperature, on the same curve as our national season map: nothing below 50°F, full speed at 78–88°F, a small penalty in extreme heat.

Weight 25%

Today 1%

ATonight's activity

Whether the population that exists will actually fly and bite this evening: dusk temperature (65–85°F is ideal), wind (they stop flying around 10 mph), humidity, and rain around sunset.

Weight 25%

Today 0%

GGround truth

A nudge from local trap counts and reports when we have them. For Minneapolis this is neutral today; the health department's surveillance is linked above and will feed this factor as we wire it in.

Weight 10%

Today neutral

SSeason gate

A multiplier from the calendar: fully open in the city's season months, half-open in the shoulder months, nearly closed in deep winter unless the week is warm. Below a 50°F weekly average the index is simply 0.

Weight ×

Today 15%

index = 100 × S × (0.40 × (0.2 + 0.8·B) + 0.25 × D + 0.25 × A + 0.10 × (0.5 + 0.5·G))

Bands: Low 0–20 · Moderate 21–40 · High 41–60 · Very High 61–80 · Severe 81–100. Weather is from Open-Meteo (observations and the 7-day forecast), refreshed hourly. The lag and temperature thresholds follow published work on Culex and Aedes development (Rueda et al. 1990; Cornell NRCC degree-day emergence; JAMCA 2024 on rainfall two to four weeks before trap peaks).

Questions people ask about mosquitoes in Minneapolis

When is mosquito season in Minneapolis?: June through September, peaking in late June and July. MMCD's season starts when degree days accumulate in spring, typically May, and ends with frost in late September or October.
Why are Minnesota mosquitoes so bad after a wet spring?: Aedes vexans lays eggs on damp soil at wetland margins; they hatch when rising water covers them. A wet spring floods thousands of acres at once, and about ten days later the metro is swarmed. A dry spring, as in 2021, means a quiet summer.
Is West Nile virus a risk in Minneapolis?: Yes, mostly in late summer: Culex tarsalis carries it, and Minnesota records human cases most years, more in the west of the state. MMCD and the Minnesota Department of Health report detections; follow them over the index.
Where does this forecast's data come from?: Open-Meteo weather for downtown Minneapolis, scored by our documented model with the northern breeding lag (10–21 days), and compared with Hennepin County's season-map climatology. Not a trap count.

Also covers St. Paul, Bloomington, Edina, Minnetonka, Maple Grove, Eden Prairie, the Chain of Lakes, Minnehaha Park: the forecast point is central Minneapolis, and conditions within about 30 miles track it closely. Weather fetched Nov 8, 12:38 PM local time.