May shattered heat records across the U.S. as sizzling warmth was reported nationwide, federal scientists announced Wednesday.

In addition, not only was it the warmest May on record across the country, but almost 8,600 local heat records were also broken or tied during the month.

“The warmth was coast-to-coast,” said climate scientist Jake Crouch from NOAA's National Center for Environmental Information. The heat was particularly noteworthy in the central U.S., especially in the upper Midwest and Ohio Valley.

On May 28, the temperature in Minneapolis soared to a record 100 degrees, the city's earliest 100-degree reading on record, buckling roads, straining air conditioners and triggering air-quality alerts.

The previous warmest May was in 1934 during the height of the Dust Bowl.

For folks in the Midwest, the crazy heat of May followed what had been an unusually cold April. In fact, for two states in the Upper Midwest — Iowa and Wisconsin — it was the coldest April since records began

Overall, the average May temperature across the contiguous U.S. was 65.4 degrees, which is 5.2 degrees above average, NOAA said.

Partly to blame for May's heat is the overall warming trend from man-made climate change, Crouch said. Also, two tropical systems helped pump warm, moist air from the Gulf of Mexico across the eastern U.S.

Another expert, Penn State University climate scientist David Titley, referring to global warming, said that "nature is dealing cards from a very different deck now compared to the 20th century.”

As for precipitation, May was very wet in the Southeast and Mid-Atlantic, part because of Subtropical Storm Alberto. In fact, it was the wettest May on record in both Florida and Maryland. In Maryland, the rain led to devastating flooding in historic Ellicott City, ruining the town for the second time in two years.

Meanwhile, more than a quarter of the contiguous U.S. remained in drought; the most intense dryness was in the Southwest.

Global weather data for May will be released later this month.

Contributing: The Associated Press