AccuWeather map, 9/28/21.
SIOUX FALLS, S.D. (KELO.com) — Parts of the nation’s midsection are dealing with an extended stretch of summer, but a dramatic temperature change later in the week will leave some feeling as if they are riding a weather roller coaster.
Temperatures shooting over 90 degrees Fahrenheit, close to 20 degrees above normal, will challenge daily records in areas throughout the North Central.
Summer weather is not quite finished yet across parts of the United States as record-challenging heat continues to build across the North Central states, sending temperatures into the mid-90s and upper 80s Fahrenheit during the first full week of autumn.
“Many locations in this region had an above-normal summer in terms of temperatures and are now starting off fall the same way,” said AccuWeather Meteorologist Mary Gilbert.
Northern cities like Billings, Montana, and Fargo, North Dakota, ran about 4-5 degrees above normal throughout the months of June, July, and August in 2021. These same locations are expected to have record-challenging temperatures this week.
“Temperatures through the northern Plains will be close to 20 degrees above normal in spots on Tuesday,” said AccuWeather Meteorologist Thomas Geiger.
In some places, temperatures began rising above average during the past weekend. Pierre, South Dakota, reached 90 degrees Sunday, marking its 56th day at 90 or higher this year, according to the National Weather Service (NWS) in Aberdeen, South Dakota. Sisseton, South Dakota, hit 91 F Sunday, barely missing the 1974 record of 92 F for Sept. 26.
“Rapid City, South Dakota, and Bismarck, North Dakota, both saw temperatures around 90 on Sunday and Monday, and it will be the same story on Tuesday,” said Geiger. These cities will barely miss out on a heat wave. A stretch of warm weather officially becomes a heat wave when a location faces two or more days of temperatures higher than the historical averages for that area.
Areas from Colorado to western Montana will have temperatures 8 to 16 degrees above average early in the week, according to AccuWeather Lead Long-Range Senior Meteorologist Paul Pastelok. Denver had temperatures rise into the upper 80s on Monday, well above the normal high temperature in the middle 70s.
Cities that approached or even surpassed record levels on Monday include Casper and Cheyenne, Wyoming; Rapid City; Kansas City and St. Louis, Missouri; Billings and Bozeman, Montana; Des Moines, Iowa; and Omaha, Nebraska.
On Monday, St. Louis hit a high of 92 F, tying the Sept. 27 record set in 2019. Omaha surpassed its Sept. 27 record of 92 by one degree on Monday. Lincoln, Nebraska, also set a new record of 94 F.
The hot conditions are expected to travel northeastward as the week progresses, propelling temperatures in places like Fargo and Bismarck, North Dakota, and Grand Forks, Minnesota, to join the dance with record levels Tuesday.
Wednesday is anticipated to be the last day of record-challenging warmth across the region, as the number of records within reach dwindles. However, Minneapolis could have a shot at reaching record temperature levels Wednesday as the forecast high is in the middle 80s. The Sept. 29 record of 89 F was set in 1897.
Even areas that don’t eye record temperatures can still have sweltering conditions this week, including Chicago and Indianapolis. Temperatures in both of those cities will soar into the upper 70s to lower 80s. These cities generally have temperatures in the lower 70s at the end of September. Wichita, Kansas, typically has temperatures near 80 at this time of year, but due to the extreme heat, temperatures can rise into the lower 90s instead on Tuesday.
Residents are recommended to take the heat seriously, as it is actually the deadliest weather phenomenon. Meteorologists recommend residents stay hydrated, wear light-colored clothes and avoid exercising outdoors when the heat is strongest.
This heat anomaly is due to an area of low pressure across the Southwest and a potent storm moving through the Northwest working together to shove an area of high pressure into the central U.S., according to Pastelok.
This high pressure will also keep precipitation to a minimum across these areas, worsening the drought situation for the region. Over 40% of the High Plains region is in a severe drought, according to the United States Drought Monitor.
For those dreaming of cool autumn weather, this period of heat is not anticipated to last too long, AccuWeather forecasters say. After Wednesday and into Thursday, temperatures are forecast to decline dramatically in some areas.
A cold front will push through the North Central states Wednesday, breaking the heat and bringing temperatures down to levels more typical of fall, said Geiger.
From Colorado to Montana, temperatures can even drop 3 to 6 degrees below average by Thursday as cold air moves in, keeping the warmest air concentrated across Minnesota, Iowa and Wisconsin, according to Pastelok.
On Thursday, AccuWeather forecasters are expecting temperatures in the lower 60s for Denver, well below average for the end of September. Temperatures will finally fall back below normal across the eastern extension of the region, including Chicago, by the weekend.
“It’ll finally start feeling like pumpkin spice season in the North Central region,” said Geiger.
(By AccuWeather Meteorologist, contributed this report.)
