Sweltering heat to challenge record highs across northern Plains, Canadian Prairies

As the intense heat over the West expands eastward by late week, AccuWeather meteorologists expect many cities in the north-central United States and southern Canada to be hotter than parts of the South.

Daytime temperatures will surge up to 25 degrees Fahrenheit (14 C) higher than early June averages from Montana to Michigan and northward through the Canadian provinces of Alberta, Saskatchewan and Manitoba during the middle and latter part of the week.

A northward bulge in the jet stream will allow the hot air to flow in just days after Memorial Day marked the unofficial start of summer.

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Mother Nature will first begin to crank up the heat on Wednesday in places such as Great Falls and Missoula, Montana, as well as Calgary, Alberta, with temperatures climbing to near-record territory into the upper 80s to lower 90s (lower 30s C). Average high temperatures range from the middle 60s to lower 70s (upper teens to lower 20s C) from north to south in this corridor.

From Thursday through Saturday, the toasty temperatures will expand eastward across southern Canada, the northern Plains and the Upper Midwest.

This heat wave is likely to bring the first 90-degree (32 C) temperatures of the year for places such as Bismarck, Grand Forks and Fargo, North Dakota, later this week. The mean first 90-degree or higher day is June 8 in Bismarck and Fargo and June 11 in Grand Forks, according to National Weather Service climate records.

In fact, it's possible that Bismarck hits the triple-digits on Friday and/or Saturday. The earliest occurrence of a 100-degree temperature in the city was May 27 in 1934.

International Falls, Minnesota; Saskatoon and Regina, Saskatchewan; and Winnipeg, Manitoba, are other areas where thermometers will be soaring into the 90s F (30s C) and challenging record highs late this week.

Temperatures will be about 5-10 degrees F (3-6 C) higher in these areas than the traditional hot spots in the Southeast, including New Orleans and Atlanta, where clouds and frequent storms will keep highs down later this week.

By Friday, Marquette, Michigan, will be nearing its daily record of 84 F (29 C) set in 1971. Thunder Bay, Ontario, may come near to its 1976 daily record of 85 F (29 C) at the end of the week as well.

"With such a prolonged bout of heat, cooling demands will skyrocket as temperatures soar. An increased cooling demand can place a strain on the power grid and residents' wallets alike," AccuWeather Meteorologist Mary Gilbert said.

With AccuWeather meteorologists calling for dry weather to accompany the heat, this will allow for opportunities to cool off at a local pool, stream or lake, without concerns of storms interrupting plans. Those spending time in the heat outside of the water are advised to drink plenty of fluids, take frequent breaks in the shade and wear light-colored clothing, to help prevent heat-related illnesses.

The intense heat will result in a worsening drought across the region, according to AccuWeather Meteorologist Jake Sojda.

Drought conditions ranging from severe to exceptional have been plaguing eastern Montana and into the Dakotas, with severe to extreme drought conditions being reported in southern Saskatchewan and Manitoba.

Above-average warmth may stick around into next week across the northern tier of the U.S. and southern tier of Canada, though there could be more opportunities for some beneficial rainfall.

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