Monday, December 22, 2025  3:10 AM 

Prepared by Bob Weisman, SCSU Meteorologist and Professor Emeritus

Shortest Days of Year Mean Temperatures Don't Behave

Yesterday was the December solstice, the shortest day of the year in the Northern Hemisphere. St. Cloud had only 8 hours, and just over 41 and a half minutes of daylight. It is the peak of the dark season, and the worst of conditions for those who suffer from seasonal affective disorder.

For weather forecasting, the short period of daylight, as well as the low sun angle, mean that the typical daily temperature trend (low temperature about an hour after sunrise, high temperature an hour or two after the sun is highest in the sky; scroll down to solar angle and intensity graph from Colorado State weather blog) is often thrown off. Note the recent temperature trend in St. Cloud (see 14-day graph of St. Cloud temperatures from MesoWest). The warmest temperature on December 8 was at midnight that evening and the December 9 temperature remained nearly the same from midnight the night before through midnight the night after. On the other hand, temperatures on December 18 were high during the early morning hours, and fell nearly all day, just holding for an hour during the early afternoon.

The reason is the short daylight period and having snow cover. Even though Minnesota now has old snow cover which isn't as bright white as the fresh stuff, incoming sunshine is still reflected by the snow cover back to space. And, if temperatures are above freezing (or even in the 20's in strong sunshine), some of the sun's heat is used up melting the snow (just getting the snow to change from solid to liquid water requires taking latent heat away from the surroundings). So, we don't warm up as much during the daylight hours. And, if it is cloudy, we don't cool off as much during the nighttime hours. So, when there are major temperature differences over a small area, the change in air mass can easily create a larger temperature change than the normal heating and cooling cycle.

Minnesota to Sit Near Large Zone of Temperature Change

Minnesota is parked near an enormous change in temperature right now. Our steering winds are now more west-to-east than south-to-north or north-to-south (see movement of weather systems on the College of DuPage North America mid-level water vapor loop). The west-to-east flow down the eastern slopes of the Rockies has created some very mild air to the south of the stalled front from Montana to Missouri, so highs were in the 40's and 50's yesterday afternoon (see 3 PM Sunday NWS WPC North America zoom-in map). Just to the north, however, is the southern edge of the extremely cold arctic air mass (temperatures in the -40's and -50's in the Yukon) with afternoon temperatures below zero in Alberta and Saskatchewan right to the US border. Any small shift in winds from southeast or southwest to north allows that huge temperature change, overwhelming the daily heating and cooling cycle.

Since the steering winds are expected to remain nearly west-to-east through the upcoming weekdays (not going to call it a work week when Christmas and Kwanzaa are ahead), any fronts that go by have this potential of either causing daytime cooling behind a cold front or overnight warming when the southeast winds kick in. The west-to-east flow also means that individual storms won't have much moisture to work with, so the storm would have to track over us or just to our south to allow major precipitation.

Some Icy Spots Possible During AM Commute, Then Above Freezing Later

Today, the warm front to our west has a shot at coming through, spreading the upper half of the 30's and even 40's that were in southwestern Minnesota yesterday (see 3 PM Sunday NWS WPC North America zoom-in map) into more of central Minnesota. There are some clouds near the front (see moving green colors pushing into Minnesota on the College of DuPage clean infrared North America satellite loop) and even a few radar echoes (see College of DuPage north central US radar loop) dropping a bit of drizzle or freezing drizzle in southern Minnesota (see NWS Aviation Weather Center METAR map). The National Weather Service has a winter weather advisory out through the morning rush hour in the Minnesota River Valley and southeastern Minnesota for the possibility for some icy coating. Central Minnesota may see a little bit of spotty ice during the pre-dawn hours.

The Minnesota Department of Transportation road reports show ice on major roads in southwestern and south central Minnesota, including south and west of Clara City on Hwy. 23. There has also been a major crash on I-35 in southern Minnesota.

Cooling During Tomorrow, Then Up We Go Again Beginning Early Wednesday

However, the edge of the cooler air to the north will push in late tonight. While overnight temperatures are going to be in the 20's to near 30, Tuesday's daytime temperatures will hold steady or fall in the 20's. The winds will shift to light southeast late tomorrow morning, so Tuesday evening temperatures in the teens will likely rise back into the 20's during the early morning hours. Highs will likely be in the 30's again on Wednesday.

Mild With Perhaps Some Fog or Spotty Freezing Drizzle Christmas

Even though we will be hanging around the front, there is the possibility of low-level moisture build-up as the week goes on, so Christmas Eve or Christmas Day travel may be slowed by some fog. And, if we have fog with temperatures below freezing, there might be some spotty freezing drizzle producing icy spots on untreated pavement.

Northern Minnesota Potential for Precipitation Thursday Night into Friday (Central Minnesota on Edge?)

There is a possibility of a storm coming closer to central on Christmas Night into Friday. At this point, St. Cloud would be near the southern fringe of the precipitation with the main snow band to our north (somewhere between Hwy. 2 and Hwy. 27, although the location is uncertain; the position shown on the Days 4-5 NWS quantitative precipitation forecast is likely a bit too far north). So, I'll be watching the progress of this storm for any possible Boxing Day travel issues.

A Colder Period Late Weekend into Early Next Week

The other trend in this week's forecast is for our mainly mild conditions to give way to a colder period from Saturday night through Monday.

Major Rain and Snow Potential in California

Nationally, the main weather-related issue is potential flooding from heavy West Coast rainfall during the middle of the week (see Days 1-5 on the NWS quantitative precipitation forecast; see Days 1-5 on the NWS WPC Excessive Rainfall Outlook). In higher elevations, there will be a risk of heavy snowfall in the Sierra Nevada mountains of California (see NWS National Discussion for more information)

Ground and Air Travel Links

• Minnesota
• North Dakota
• South Dakota
• Nebraska
• Iowa
• Wisconsin
• Manitoba
• Ontario
• Air Travel Delays and Cancellations from FlightAware.com

Detailed St. Cloud, MN, and Vicinity Forecast

Confidence Level: "The Bugs Are Waiting for Me to Mow the Lawn"

Monday 12/22/2025: Perhaps some icy spots on areas roads early. Mostly cloudy with a few sunny periods and milder. Maybe a flurry or a sprinkle. High: between 35 and 40. Winds: SE 5-10 MPH. Chance of measurable precipitation: 10%.

Monday Night: Partly clear, light winds, and still mild. Low: between 25 and 30. Winds: light evening, NW 5-10 MPH during the early morning hours. Chance of measurable precipitation: 10%.

Tuesday 12/23/2025: Sunshine through high clouds and back to seasonable cold. Temperatures slowly falling through the 20's. Winds: NW 8-15 MPH, diminishing during the afternoon. Chance of measurable snowfall: 10%.

Tuesday Night: Clouding up, a light breeze and turning milder again. Evening temperatures in the teens, rising above 20 by early morning. Winds: SE 5 MPH evening, 5-15 MPH early morning. Chance of measurable precipitation: 10%.

Wednesday 12/24/2025: A mixture of sunshine and low clouds, breezy, and milder. High: between 30 and 35. Winds: SE 5-15 MPH. Chance of measurable snowfall: 10%.

Confidence Level: "Extra Bugs Will Come From Every Home on the Block to Hover Around My Head"

Wednesday Night: Continued mild. A chance for low clouds and fog. Low: between 20 and 25. Winds: N-NE 5-10 MPH. Chance of measurable precipitation: 10%.

Confidence Level: "Enough Bugs Will Fly into My Mouth to Throw Off My Diet

Thursday 12/25/2025: Cloudy, breezy, and a bit colder. Perhaps some freezing drizzle or flurries. High: between 28 and 34. Winds: E 8-15 MPH. Chance of measurable snowfall: 10%.

Thursday Night: Cloudy with occasional snow or mixed precipitation. Low between 26 and 32. Winds: E 5-15 MPH. Chance of measurable precipitation: 30%.

Friday 12/26/2025: Mostly cloudy with perhaps some afternoon sun. Continued mild. High: between 30 and 35. Winds: SE 5-15 MPH. Chance of measurable snowfall: 20%.

Extended: Brief period of colder weather Saturday night through Monday???? Uncertain but small precipitation chances???

Forecast Confidence (10 - "The Rabbits Will Thump Even Though I Fed Them"; 0 - "The Rabbits Will Offer To Groom My Bald Spot"): 7 Monday, 8 Monday night through Tuesday night, 7 Wednesday, 5 Wednesday night, 3 Thursday, 2 Thursday night and Friday.

Yesterday's High: 22°F; Overnight Low (through 3 AM Monday): 10°F
St. Cloud Airport 24-Hour Melted Precipitation (through 3 AM Monday): None; SCSU 24-Hour Precipitation (through 3 AM Monday): None

Next Update: Tuesday, December 23, 2025 6 AM

Let me know what you think about this forecast and discussion by emailing SCSU meteorology professor Bob Weisman. Please note that I make the forecast, not the weather!

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