Mosquitoes may reach five-year high this summer in Twin Cities area

Mosquitoes may reach a five-year high by the Fourth of July.

That’s the buzz from the Metropolitan Mosquito Control District, which says that, based on its models, the flying pests will surge to numbers not seen since 2020.

“We can be certain about that,” said MMCD spokesman Alex Carlson.

The cattail species has been largely absent over the past three years due to drought conditions. Last year was an anomaly in that a bumper crop of mosquitoes did not materialize after an extremely soggy May and June.

But this year, the cattail species that emerges in the midsummer is poised for a comeback, Carlson said.

“Most people will notice,” Carlson said, especially those who live near marshes and other mosquito-producing habitats. “We’ll easily surpass the levels of the past five years.”

The forecast for early spring mosquito-free days is a bit more promising as a lack of snow on the ground and lower river levels may keep the count of Aedes species below average. Aedes are one of the earliest to hatch.

The state saw record numbers of Aedes in 2023 and high numbers last year. This year, seasonal wetlands look to be dry. That combined with a lack of snowpack could keep their numbers down.

“We could be off to a good start,” Carlson said.

Of course, that could all change if the skies open up and April turns out to be moist, Carlson said.

April started on a wet note in many parts of the state.

That included rain and snow, including 3 inches of snow in Red Wing, Eagan and Woodbury, 2.8 inches in Farmington, 2.5 in Maple Plain and Isanti, and 1.7 inches in Rochester, the National Weather Service said.

On Wednesday, northern Minnesota is in line for a big dumping of snow, with 4 to 10 inches predicted in an area from Brainerd to Duluth to International Falls. More than a foot could fall along the North Shore of Lake Superior, the National Weather Service said.

A cooler spring could slow down the emergence of Aedes, but wet and warm conditions will bring them out.

The MMCD is predicting lower numbers of black flies at the beginning of the season.

The agency tracks the number of days above 40 degrees to determine when to start its annual treatment of 200,000 acres of wetlands in the metro. Based on that, Carlson said the MMCD is planning to begin treatment around April 19, a little later than last year.

Floodwater mosquitoes are the most common of the 52 varieties found in Minnesota, and their presence is often determined by how much rain falls. For humans, the outlook is favorable as the forecast from the Climate Prediction Center calls for better odds of above normal temperatures and below average precipitation in June, July and August.

But a mosquito forecast that is weather dependent “is hard to predict,” Carlson said.