South Dakota Mosquito Forecast

South Dakota's winters shut mosquito activity down for months — but snowmelt and standing water then drive a sharp surge from late May into early September. Pressure is low across the calendar as a whole, yet spikes hard at the peak.

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When is mosquito season in South Dakota?

South Dakota's mosquito season runs from late May into early September. Activity ramps up once overnight lows hold above about 50°F, and surges in the two to three days after rain, when fresh standing water triggers a new hatch. The window is short, but it can be relentless while it lasts.

Where are mosquitoes worst in South Dakota?

Within South Dakota, the most consistent pressure tends to land around Sioux Falls, Rapid City, and Aberdeen. Low, wet ground near these areas turns spring snowmelt and rain into prime breeding habitat. Anywhere near rivers, marshes, lakes, or recent flooding will read higher than the surrounding area — exactly the kind of local detail the live map above is built to show.

How the South Dakota forecast works

MosquitoCast estimates South Dakota's mosquito activity from live weather — temperature, humidity, wind, and recent rainfall — layered on the area's long-term rainfall climate, elevation, and terrain, and refreshed every day from NOAA's forecast data. It's the same model nationwide, so the reading for South Dakota is directly comparable to anywhere else in the country.