CHICAGOANS experienced the COOLEST DAYTIME TEMPS FRIDAY of the past 3 months—and the early season chill is hardly the norm for the day. 

The day’s (Sept 9’s) official high is likely to end up 68-deg at O’Hare.  That’s the coolest daytime high temp since 68-deg back on June 16^th and 65-deg on June 13th

The loss of daylight begins impacting the temps here more frequently this time of year and forward—even the period of daylight we see here in Chicago began slowly decreasing after Juen 21st.  That decrease is accelerating as we move deeper into autumn.  Chicagoans saw 145 minutes (2.32 hrs) LESS DAYLIGHT in Chicago than back on our LONGEST DAY OF THE YEAR and the opening day of astronomical summer:  June 21st.

The period of daylight will continue its seasonal decrease. We’ll see another 61 minutes of daylight disappear in Chicago over the  remaining  days of September in Chicago. 

It was 84 on this date a year ago.  And previous Sept 8^th high temps since records began in Chicago in 1871have failed warm out of the 60s only 22 OF THE PAST 153 YEARS—that’s just 14% of Sept 9’s!  That means roughly 9 to 10 Sept 9’s have ended up with temps warmer than today’s.

The air sweeping with the day’s northerly winds over the warm waters of Lake Michigan generated the season’s first LAKE EFFECT rains in lakeside counties Friday.

THINK THE WARM WEATHER IS OVER???? Not on your life!  There surely will be cool spells—and THEY WILL ARRIVE with slowly increasing frequency in the weeks and months to come.  But weather history shows us 100% of years since 1942—have produced 70, 75 and 80-deg high temps from Sept 9^th forward.   93% of those 80 years have produced 85-deg highs—and even just over one third of years since 1942 have produced a 90-deg high.

By the way, 1942 was chose because it’s an important year for Chicago’s weather records. That’s because  Midway Airport became the official observation station that  year—and the official site switched to O’Hare in 1980. So, 1942 marked the beginning of the era in which Chicago’s official temps began being taken at Midway and O’Hare.

HERE’S WHAT’S AHEAD AS WE HEAD INTO THE WEEKEND AND BEYOND: 

The lake effect cloud set-up will linger into Saturday morning along Lake Michigan. Precip chances are diminishing with it, however.

The weekend is to see north to northeast winds continue but high pressure is to settle over the area and produce increased sunshine once lingering lake cloud patches begin to slowly  dissipate Saturday.  Sunday promises a good deal of sunshine.

A bit of warming is due Sunday with temps within striking distance of 80-degrees but cooling with a reinforcing cool push the opening half of next week 

Modeling suggest rain chances increase Monday into Tuesday—but next week will average close to 11-deg cooler than this week.

A temp rebound appears in the offing next weekend into the week which follows.

HERE’S MY LATEST FRIDAY CHICAGO METRO FORECAST (9/8/2023)

BEACH HAZARDS STATEMENT EXPIRES at 1am SATURDAY MORNING.

TONIGHT: Variable cloudiness continues near Lake Michigan—while some clearing occurs inland. COOL for the season.  Low 58—but low 50s inland.

SATURDAY: Some cloudiness along and near Lake Michigan.  But clouds are to diminish slowly through the afternoon. Cool north to northeast winds continue producing a chop on Lake Michigan for weekend mariners.  High 73—but 60s beaches and lakeshore.

SATURDAY NIGHT: Scattered clouds and cool.  Low 57 with low 50s again inland.

SUNDAY: Partly sunny, temps a bit warmer by afternoon and closer to seasonable early September temperatures.  High 78—but closer to 70 along Lake Michigan.

MONDAY: Becoming cloud,  cooler. Growing prospects for showers. High Monday 72.  Low Monday night 58.

TUESDAY: Cloudy at times, breezy and cooler. Some showers possible. High 68.

WEDNESDAY through FRIDAY: Partly sunny days and partly cloudy night.  Cool temps Wednesday and Thursday—warming a bit Friday.  High Wednesday 66. Thursday’s high 69—and the high Friday 75.