Is another abnormally hot summer on tap in Minnesota? The odds are 50-50

After last year’s broiling summer that saw the fourth most 90-degree days in Twin Cities record-keeping history followed by the warmest winter on record, is another sizzling summer on tap for 2024?

Flip a coin, says the Climate Prediction Center, which is out with its forecast for the next three months. The arm of the National Weather Service gives Minnesota and most of the Dakotas equal chances of having warmer- or cooler-than-average temperatures during meteorological summer covering June, July and August.

“That said, a warm summer doesn’t necessarily mean lots of 90-degree days,” said assistant state climatologist Pete Boulay.

Last summer’s daily average temperature of 74.7 degrees tied for the fifth warmest on record. The mercury hit 90 degrees or higher 33 times, tying for the fourth most in a season. But many years that rank among the metro area’s hottest summers didn’t see high numbers of 90-degree days. Among them were 2022, 2011, 2010, 2006, 2005, 1983, 1921 and 1894.

On average, the mercury hits or surpasses 90 degrees 13 times during the summer in the Twin Cities, based on averages from the 30-year period from 1991 to 2020. In northern Minnesota, thermometers read 90 degrees or above an average of one to three times during the season, while southwestern and western Minnesota average 20 days a year, according to the Minnesota Climatology Office.

The hottest summer on record was 2021 when the average daily temperature at the Minneapolis-St. Paul International Airport was 75.6 degrees. That year 27 days had temperatures 90 or greater, which is tied for 10th on the list of hottest summers dating back 151 years.

In 1988, the metro area saw 44 days with readings at 90 degrees or higher with the hottest day at 105 for the most 90-plus readings ever. Yet that year still ranks only second on the list of warmest summers, according to weather records.

Sometimes, the metro area doesn’t even see a 90-degree reading. That happened during the summers of 1902, 1915 and 1993, the Climatology Office said.

Many places in Minnesota are coming off the warmest winter on record. That includes International Falls, Rochester, St. Cloud and the Twin Cities, the Climatology Office said. And there are markers that the warming trend could produce another scorching summer.

Globally, last year was the warmest since record-keeping began in 1850, the National Oceanic Atmospheric Administration said.

“Looking ahead, there is a one-in-three chance 2024 will be warmer than 2023, and a 99% chance that 2024 will rank among the top five warmest years,” the agency said.

The desert Southwest and New England stand the greatest chances of having well above-average temperatures while the rest of the country has a 30% to 60% chance of sweltering, the Climate Prediction Center said. Minnesota, the Dakotas and part of Iowa were the one exception.

“There isn’t great guidance for most of the state,” Boulay said about the prediction center’s long-range forecast.

Precipitation plays a factor in how hot a summer will be. The 10 summers in Minnesota with the most 90-degree days correlate with dry summers, Boulay said.

“Many years on that list are drought years, and it remains to be seen if 2024 will be one of those years,” Boulay said. “At least in the near term, probably not, but we could also dry out fairly fast in the summer.”

The Climate Prediction Center gives Minnesota and much of the Upper Midwest “equal chances” of seeing normal rainfall.

Some of that rain occurred overnight Sunday into Monday morning with another round set to move in Tuesday, the National Weather Service in the Twin Cities reported. Storms that may become severe could bring 1 to 2½ inches of rain Tuesday before things dry out Wednesday.

High temperatures will hang out in the 70s all week, except Wednesday when readings will slip into the 60s. The early Memorial Day weekend forecast calls for a slight chance of showers on Friday but mostly sunny on Saturday and Sunday with temperatures in the 70s, the Weather Service said.