Enjoy the 60s while you can: Colder air arrives this week

Staying Mild:

If you loved the weather this past weekend, you'll enjoy the start of the new week as well. High pressure settling overhead will keep conditions quiet through much of the day, allowing for periods of sunshine and mild November temperatures. After a chilly start, we can expect temperatures to steadily climb to similar levels to Sunday, leaving us in the low 60s.

High pressure will remain parked nearby tomorrow, helping sunshine and pleasant conditions to stick around for another day across the area. 

Much like today and Sunday, we'll start off on the chilly side during the early morning hours before temperatures rebound nicely. Despite winds being out of the northwest, afternoon highs are expected to reach the low 60s once again.  

Midweek Storm System:

Changes arrive in the weather pattern on Wednesday as a clipper-like system dives southeast into the Great Lakes region. While this system will bring the chance for scattered showers during the day, especially for those along and south of I-88, the bigger story will be the colder air that follows in its wake.

 

Temperature Trend:

A reinforcing shot of chilly Canadian air will spill in for the latter half of the week, knocking temperatures back below-average. Highs are expected to reach the low 50s on Wednesday, then drop into the low 40s for Thursday and Friday. Compared to mid-November standards, this is 5° to 10° below average. Overnight lows will end up in the upper 20s. 

November chill sets up lake effect machine later this week

 The weather pattern will be rather quiet over the next couple of days with some milder afternoons featuring highs in the low 60s and overnight lows in the middle 30s to around 40. The only feature of note through Tuesday night will be some patches of frost or fog each night.

Our next weather system will arrive Wednesday along the leading edge of a strong push of cool Canadian air. This will bring scattered showers our direction through much of Wednesday and even early Thursday. All told, most will only see less than a couple tenths of an inch of rain.

The cooler air rushing in behind the system will set up a cold Northerly wind, kickstarting lake-effect precipitation on the Southern coasts of the Great Lakes. Some of this Canadian air may be just cold enough to mix in some pockets of snowflakes, which would mark the first of the season for some. Far Northern Illinois looks to be just far enough removed from the moisture Friday and Saturday, which should keep us dry compared to those East of us. But it will be cold and breezy with afternoon highs only in the middle 40s Thursday through Saturday.

I know we may not want to talk about "s-n-o-w" quite yet, but it will be here before we know it! On average, Rockford sees its first trace of snow around Halloween and the first 1" snowfall around early December. The earliest measurable snow in Rockford's history was October 12th, 1909. One year ago today brought Rockford's first snow of the 2025-26 winter season, with 1.2" falling at the airport. So, at the very least, this season's first snow will be a bit later compared to last year.

Mild few afternoons, fall chill returns later in the week

 While it will be a bit breezy Sunday, temperatures will still rise near the 60-degree mark. Similar numbers are expected with high pressure overhead Monday and plentiful sunshine Tuesday. Overnight lows may be chilly, particularly Sunday night. But overall, temperatures will be running a few degrees above what is typical for this time of year, at least for a couple days.

Our next push of cooler Canadian air will arrive with a passing weather system Wednesday and Thursday. This will bring some pockets of light showers our way, then some lake effect precipitation across the Eastern Great Lakes before the weekend. While we will likely be far too dry for anything here, parts of Northern Indiana, Michigan, and Ohio may see some of the white and fluffy stuff. Our main impact will be the fall chill, as highs return to the 40s to close out the week.

Widespread frost tonight, elevated surfaces could become slick

 Friday was a chilly day in the Stateline despite the abundant sunshine. The afternoon high of 49 degrees marked the coolest high since we saw only 44 degrees April 7th, over 200 days ago!

A clear sky tonight will work to enhance radiational cooling, where the solar radiation built up from the day escapes into space. This will lead to a cold night with overnight lows in the upper 20s! A bit of surface moisture will likely allow for a widespread frost to develop. A few elevated surfaces (such as decks or balconies) may become slick! I do not expect any issues to roadways, however.

This weekend will start on a cool note again, as afternoon highs will only rebound to the low 50s Saturday afternoon, but near 60 on Sunday. A few passing upper level clouds will not block out too much sunshine. While not as cold, overnight lows will remain in the 30s the couple nights to follow.

Stateline weather whiplash: 20s tonight, near 60 Sunday

Mild Nights No More:

With how mild this fall has been, freezing overnight temperatures have been hard to come by. In fact, we here in Rockford have only recorded one morning low at or below freezing so far this season. 

That all changes tonight. After a partly cloudy Friday with afternoon highs in the upper 40s, temperatures will tumble quickly after sunset as colder air settles into northern Illinois and southern Wisconsin. Low temperatures are expected to drop into the upper 20s, making it the coldest night of the season thus far and setting the stage for some frost by sunrise Saturday morning. Those with any remaining sensitive plants outdoors will want to take the necessary precautions before heading to bed this evening. 

Mild Weekend:

Fortunately, the taste of winter won't stick around for long. While temperatures plunge into the upper 20s tonight, milder air quickly returns for the rest of the weekend. Saturday will feature mainly sunny skies with afternoon highs in the low 50s. 

Temperatures will settle into the low 30s by Sunday morning, allowing another round of patchy frost to be possible, particularly in areas that dip closer to the freezing mark. After a chilly start, temperatures rebound nicely by Sunday afternoon, with highs returning to around the 60-degree mark. This mild stretch continues into next week as we hold onto ridging and a southwesterly wind.

Thursday chill continues, Increasing showers by evening

 

As a cold front now moves into southern Wisconsin and northern Illinois we are beginning to see a few pockets of drizzle, mist, and light showers developing. This precipitation will continue through the rest of the afternoon and evening, coming to an end slowly during the overnight.

Temperatures have remained on the chilly side, although right around where we should be for the average high temperature. Once the cold front clears

the Stateline later this evening a push of cold air is set to move in, bringing temperatures a few thousand feet above the surface below zero. However, temperatures at the surface won't nearly be that cold, although we could see overnight lows dip into the mid-30s. But that chill all depends on just how fast the clouds from the overnight clear out. If the clouds hold tight through the morning, then temperatures won't be quite as cold. If, though, clouds clear before sunrise then there may be a couple hour window where temperatures fall into the low to mid 30s.

I suppose if there is some good news to look at going into Friday it is we should see a return of sunshine as the pesky low clouds finally depart for the afternoon.

Brief dip in temperatures by the end of the week

 
Temperatures will take a little bit of a tumble by the end of the week as a push of colder air arrives Thursday night. This cooler air mass arrives behind a cold front that'll move through the region Thursday afternoon. Temperatures Thursday will only warm to the low 50s thanks to cloud cover and a wind shift around to the northwest. Winds will be gusty at times around 20-25 mph.

As the clouds begin to clear late Thursday night a much cooler air mass will move in causing temperatures to fall into the 30s early Friday morning. Should clouds be a little slower to leave then overnight lows will remain in the upper 30s. If, however, clouds clear a little faster into Friday morning then temperatures could fall into the low 30s. Despite the sunshine expected for Friday, afternoon temperatures will only reach the upper 40s/low 50s.

High pressure to our north Friday afternoon will sink into northern Missouri Friday night allowing temperatures to fall into the upper 20s early Saturday morning. Frost will be likely in the morning, but since the growing season has ended the issuance of any frost or freeze headlines are done for the fall season. While the next few nights will be chilly, they won't be too far from where the average low should be - in the low to mid 30s. Low temperatures the last several nights (and really for the last couple of weeks) have been mainly above average, with the last few nights well above average! So, while yes, it will feel chilly heading into the weekend we are not too far off from the average.