St. Cloud, MN Weather Forecast

Hottest Day in Nearly 3 Years Yesterday

Yesterday was by far the most oppressive day of this summer. Dew points (green number at lower left on yesterday's 4 PM CDT North America zoom-in map) were in the Florida-like low to middle 70's in central Minnesota with some hurricane-like upper 70's and lower 80's in southern Minnesota and Iowa (set time to 19Z-22Z, 2-5 PM, on the NWS Aviation Weather Center METAR map). Heat indices were over 100 degrees in most of central Minnesota with even some 110's in Pipestone and Windom (set time to 3-5 PM on the NWS Minnesota hourly weather round-up). The St. Cloud Sky Central Airport reached a high of 97 degrees (see NWS: last 24 hours of St. Cloud observations), St. Cloud's hottest high temperature since August 22, 2023. The last time St. Cloud was hotter than 97 degrees was June 20, 2022, when the high reached 101, which was the first 100+ temperature in 11 years. Yesterday afternoon's lower 70's dew points produced a top heat index of 104 in St. Cloud.

Note from the bottom of the August 2024 St. Cloud weather summary (you'll have to scroll down) that there have only been 7 previous high temperatures of 97 degrees or hotter since 2006. Yesterday makes it 8.

Overnight Thunderstorms Few and Far Between

All of that hot air also produced a warm pocket of air aloft, so overnight thunderstorms have been limited to northern Minnesota between the Rainy River and Duluth (see College of DuPage North America clean infrared satellite loop). 

Hot Again Today, But Turning Drier, Perhaps Smokier

The main low over Hudson Bay (see counterclockwise circulation on the College of DuPage North America mid-level water vapor loop) has edged eastward in the past day. That system will eventually pull the cold front in the Dakotas (see 24-hour loop of NWS WPC surface maps) through central Minnesota by afternoon. The air immediately to the west of the cold front was just as hot as what we had yesterday (note the 100-plus temperatures in the western Dakotas on yesterday's 4 PM CDT North America zoom-in map). The difference was that the dew points ranged from the comfortable 50's to the desert-like 20's in the western Dakotas. Those readings weren't much different than those from interior southern California or southern Nevada at 4 PM CDT (a few places touching 110 degrees, but with similar dew points).

Given the smaller chance for leftover clouds this morning (thunderstorm risk to our east on the NWS Storm Prediction Center Day 1 convective outlook) than yesterday morning, I expect another really hot day (highs well into the 90's, perhaps brushing 100 degrees), but the dew points should drop back into the lower 60's or even 50's when the front comes through around midday. So, the National Weather Service has a heat advisory from the Twin Cities Metro southwestward to Jackson and Fairmont and southeastward past Rochester and LaCrosse to the Iowa border (see orange on the NWS Twin Cities watch-warning map). The extreme heat warning (red) has been pushed south and east, mainly in Iowa and Wisconsin, but also in Houston County in Minnesota (including Caledonia and LaCrescent), especially along the Mississippi River Valley. 

That drier air may come with some smoke. Note the smoke (04) and haze (05) weather symbols in western North Dakota. That smoke is near the ground, producing red air quality indices (unhealthy for everyone) from western North Dakota northward and westward. Thus far, the Minnesota Pollution Control Agency is keeping the forecast AQI in the moderate category, but we'll see. That factor could keep the temperatures short of 100 degrees today. 

And, fire danger will continue to be high in northern Minnesota, as long as we remain very warm to hot (note red for Tuesday and Wednesday on the NWS Heat Risk forecast).

You can track the afternoon high temperatures, dew points, and heat indices on the NWS Minnesota hourly weather round-up.

Not Quite as Hot Tomorrow, But Heat and Humidity Returns Late Tomorrow(?) Wednesday(!)

The humidity will tend to return by tomorrow afternoon. The highs will be limited to the upper 80's to perhaps 90. That may push heat indices towards 95. By Wednesday, we have a chance for the heat (highs in the lower 90's) and oppressive humidity (dew points back in the upper 60's to near 70) to return, so Wednesday's heat stress may be similar to Saturday. Note the wider area of red on the NWS Heat Risk forecast on Tuesday and Wednesday than today.

Best Chance for Needed Rain on Thursday?

Thursday still appears to be our next best chance for widespread showers and thunderstorms (see Days 4-5 of the NWS WPC quantitative precipitation forecast). The severe weather threat is uncertain at this point. However, I wouldn't count on that prediction, given how many recent storm threats have fizzled.

Roller Coaster Temperature and Humidity Friday into the Middle of Next Week?

Friday has the potential for slightly cooler and considerably drier conditions with highs back in the 80's and potential lows in the 50's. Saturday may hang on to those conditions, but another brief shot of hotter air could be on tap for Sunday and Monday. The long-range forecasts show a stronger surge of Canadian air, which would potential mean cooler, drier, but smokier air Tuesday and Wednesday.