Minnesota is in the midst of a sizzling stretch of summer-like weather. Something unique for this time of year. 

A packed Nokomis Beach, soaked in sunshine and steaming close to 90 degrees, would make you think it’s a mid-summer day. But it’s just mid-May.

Several beachgoers WCCO talked with described the day as hot but bearable thanks to a lake breeze. 

Still, temperatures that feel like late July for a four-day stretch had them calling it a heat wave.

What defines a heat wave?

“I think it’s in the eye of the beholder,” said Ken Blumenfeld, a senior climatologist with the Minnesota Department of Natural Resources.

According to the National Weather Service (NWS), a heat wave is a “period of abnormally hot weather generally lasting more than two days. Heat waves can occur with or without high humidity.” 

There was no specific temperature listed, but the NWS added that a heat wave often involves dangerously hot weather that could harm people.

Blumenfeld looks at heat waves from a statistical perspective. “In climatology it’s just extreme warmth relative to the time of year,” he said.

May 11 to May 14, the daily high temperature hit or was forecasted to land around 90 degrees. The average high for this time of year is around 67 to 68 degrees according to the National Oceanic and Atmospheric Administration (NOAA). That means the Twin Cities is running least 20 degrees warmer than usual.

“If it’s supposed to be like 60 right now but right now, we’re having all this heat, it’s gotta be a heat wave,” said Ambuskah Little Voice while at the beach with friends.

Blumenfeld also understands that public health workers have their own definition. 

“[They] might consider a heat wave to be something that could cause human bodies to have problems keeping itself cool naturally,” said Blumenfeld.

That’s usually in peak summer when high humidity combines with high temperatures, creating dangerous conditions leading to heat stroke and exhaustion. 

“Heat during late May and even late September and October tends to be really dry compared to the kind of heat you get in July and August,” said Blumenfeld.

If nights are comfortably cool, is it still a heat wave?

“That’s where it gets a little iffy,” Blumenfeld said.

A heat wave in mid-summer could have nights in the 70s while the air remains thick. In May, the daily low temperatures have settled in the 60s and even 50s, creating a difference of 25 to 30 degrees, even larger during this current heat wave. The air also pleasantly dry.

Could you have a heat wave in the winter?

Beachgoers said both yes and no. Heat isn’t a word typically associated with the coldest time of year, but there’s no denying that it still arrives in surprising fashion.

“We can have heat waves in winter if you’re looking at it statistically,” Blumenfeld said.

Consider late December 2023, the Twin Cities hit 55 degrees on Christmas Eve, then 54 degrees on Christmas day along with relatively high humidity. That’s extreme warmth for the holiday season, heating up the debate on how to label these steamy stretches.

“Defining a heat wave really kind of depends on who’s asking,” Blumenfeld said.

The most recent extreme heat for the month of May came in 2018. That’s when much of Minnesota hit 100 degrees on Memorial Day.

FREDENBURG, Minn. –In the Land of 10,000 Lakes, the fishing opener is like an unofficial holiday for Minnesotans.

“It’s more than just a date on the calendar. It’s a tradition. It’s really kind of the kickoff to summer, it’s an essential part of being a Minnesotan,” Emily Manning, Fredenberg Minno-ette Inc. Store Manger said.

Across the state, boaters hit the water looking for some of Minnesota’s most popular fish including walleye, bass, and northern pike. But first, they hit the bait and tackle stores, including the Fredenburg Minno-ette just north of Duluth.

“I know it was good for our store, as well as all the bars and resorts around here. It’s a huge boost after a long winter for this area,” Manning said.

At the Minno-ette, live bait and lures were the hot ticket items. The shop was also stocked up with snacks, rods, nets and gas.

“We are a sporting goods store, a bait store, gas, general. We kind of have a little bit of everything, since we’re, located on the outskirts of town,” Manning said.

Anglers got an early morning start on Saturday as many lined up at four in the morning to pick up some last minute items, and it sounds like it was a successful opening weekend out there on the water.

“Sounds like people were doing really well. Some of the people that got here right at 4am actually came back around 9 because they had gone through all their bait. They were killing them out on Fish Lake for walleye, from what I’ve heard,” Manning said.

With the warm temps this year, anglers were ready to get their gear and bait and reel in big one.

“They’re always crazy busy for us. Thankfully, there was no, you know, horrible rain or wind or anything like that. So it’s, it’s been pretty on par with past seasons,” Manning said.

With Fredenburg being such a tight knit community, many of the opening day anglers make their stop at the Minno-ette an annual thing.

“This time of year, we get to see a lot of familiar faces, like the snow bird people who are coming back up to their cabins. And that’s always nice to just kind of rekindle that connection as well,” Manning said.

With the opener in the books, the season ahead looks to promise many early mornings and big catches.