Muggy in Minnesota: State is setting summer records for heat and humidity

If you think it's been hot, muggy and wet in your corner of Minnesota, you're right — and the numbers prove it.

From International Falls south to the Iowa border, Minnesotans are experiencing a sticky summer that is setting weather records in many parts of the state.

And if you're looking for a villain, blame Canada. It's the absence of Canadian air masses that is behind our horrid heat and humidity, said Pete Boulay, a climatologist with the Minnesota Department of Natural Resources.

"We have not had many days where you had a [Canadian] cold front survive the trip south to drag in some cold air," he said. "It's been warm, moist air from the Gulf of Mexico.

"We can't get that air mass out of here. It just kind of lingers."

In the Twin Cities metro area, the first six weeks of summer have been the hottest and muggiest ever, said Dan Luna, a meteorologist with the National Weather Service (NWS) in Chanhassen.

Overnight low temperatures since June 1 have averaged 62.1 degrees, the hottest nighttime temperatures ever. That's two degrees higher than in 2012, which ranked second. Meanwhile, the average high temperature this summer in the Twin Cities is 80.7 degrees, the third-highest average for a summer in the metro area.

Adding the day and night temperatures yields an overall average temperature of 71.4 degrees — again, the highest average ever for the first half of summer.

Since June 1, the Twin Cities has racked up 13 days with a high temperature of more than 90 degrees. That's typically the number of 90-plus degree days for an entire year, Luna said.

The metro area also has experienced a string of days with a heat index — measuring the impact of both heat and humidity — of more than 100. The NWS doesn't keep heat-index records, Luna said, but "this has been one of the most oppressive summers in a long time."

And then there's the rain. Pockets of the state have been hit hard by severe thunderstorms. Southwest Minnesota has had five to eight times the normal amount of rain in the past month, Luna said. So have Itasca, Pine and Kanabec counties in east-central Minnesota. Northern Minnesota from International Falls south to Lake Vermilion has recorded more than five times its normal rainfall in the past month.

Some of the worst storms have hit farmers in southern Minnesota along the Interstate 90 corridor, said Dave Nicolai, an educator with the University of Minnesota Extension service.

"If I looked at Minnesota crop agriculture, it is what I would call 'the tale of two cities,' " Nicolai said. "It was the best of times and the worst of times, depending on where you farm."

Across much of southern Minnesota, planting was delayed by a wet and cold April. Then frequent storms flooded fields and stunted crop growth. The state is seeking federal disaster aid for 36 counties and one tribal nation affected by the storms; state officials said damage estimates aren't yet complete

Meanwhile, the Red River Valley, the site of frequent flooding in recent years, is one of the driest areas in the state, Nicolai said.

"We have crops that are looking very good in the east-central and south-central part of the state," he said. "You know the old saying, 'Knee high by the 4th of July?' This year we had corn that was head high on the 4th of July.

"The bottom line is, we're optimistic. By and large, the state will still produce some good crops. But if you're farming the southern area along the I-90 corridor, you faced a lot of challenges."

But relief is in sight. A Canadian air mass is expected in the coming week, Luna said, "which should make a lot of people happy."

John Reinan • 612-673-7402