The upper Midwest and Great Lakes have essentially skipped spring this year, leaping from winter to summer.

Only a few weeks ago, ice finally finished melting on Minnesota’s lakes. Now the state is witnessing 100-degree heat. Minneapolis surged to the century mark on Memorial Day, the earliest instance in recorded history. It hit at least 90 degrees on six straight days, a May record.

The experience in Twin Cities, which had its fourth coldest April on record, has been repeated all over the upper Midwest and Great Lakes. Historic heat has followed historic cold.

As recently as April 18, Madison, Wis., was pasted by seven inches of snow, with highs in the low 30s. From May 26 to 29, it posted four straight 90 degree-days, for the first time on record during the month.

The weather desk of Radiant Solutions, based in Gaithersburg, Md., rounded up a remarkable set of heat milestones established across the region since Friday:

  • Chicago set record highs of 97 and 95 degrees Sunday and Monday, only the second time it has endured back-to-back 95 degree days in May on record.
  • Milwaukee and Toledo established record highs for May of 95 degrees (Sunday) and 98 degrees (Monday), respectively.
  • Omaha and Green Bay, Wis., set record highs on four straight days Friday to Monday.
  • Des Moines set record highs on three straight days Saturday to Monday, including its earliest 99-degree reading on record Sunday.
  • Muskegon, Mich., hit 96 degrees Tuesday, a monthly record. reported over 1,900 daily heat records were tied or broken across the U.S.

Peter Mullinax, lead meteorologist at Planalytics, tweeted that Minneapolis’s May warm-up from April was the biggest on record, a rebound of almost 30 degrees. Indianapolis, Dallas and Chicago have also witnessed their biggest April-to-May jumps, he found.

“You could find a LOT of Heartland locations that join Chicago, Minneapolis, or Dallas,” he tweeted.

On Tuesday, highs soared into at least the mid-90s from Kansas to Central Michigan. The heat was forecast to ease Wednesday but gradually build back into the Central Plains through Friday, before finally retreating far to the south by the weekend.

The swing in temperatures reflects a radical change in the jet stream pattern over North America. Whereas this fast-flowing river of upper-level winds, separating cold from hot, dipped into Texas and the Southeast during April, it has since quickly retreated into Canada.

Much warmer-than-normal weather has covered almost the entire Lower 48 states during May. A preliminary analysis indicates it may well become the warmest May on record passing 1934, which coincided with the Dust Bowl.

Some of the unusually cold weather that tormented the upper Midwest in April found its way into the town of Gander, Newfoundland, in eastern Canada, which was buried under more than a foot of snow last week.