WINDY, COOLER—almost autumnlike cool air is to sweep into Chicago on “NNE” winds which arrive after a long, wave-generating trek southward the length of Lake Michigan Tuesday night and Wednesday.

The time such winds spend over Lake Michigan equips them uniquely to develop waves and rip currents—and these features are behind the BEACH HAZARDS STATEMENT which is in effect on our Chicago area beaches into Wednesday night. White-capped waves will populate the lake surface later tonight and Wednesday and swimmers will find water treacherous for swimming Wednesday.

We have only 2 days left in August and the 3 month meteorological summer season, which spans June, July and August. Seven of the past 8 months have posted TEMP SURPLUSES IN CHICAGO—and though the temp surpluses in each of the Summer 2023 months have been MODEST—the summer season had managed a 3-month average temp which is among the 20% warmest of any of the past 153 summer seasons here.

The cool temps riding into the area will be a bit jarring after Tuesday’s mid 80s—BUT THEY’LL NOT LAST LONG.

Forecast models continue to build a formidable dome of LATE SEASON HOT AIR which, as early as Saturday afternoon, will begin producing 90-deg and higher daytime temps.  The string of 90s this hot air dome is likely to generate appears likely to extend through Sunday, Monday, Tuesday—and even into Wednesday next week—-WELL TIMED FOR THE UPCOMING LABOR DAY HOLIDAY WEEKEND.

September, Chicago’s 3rd fastest cooling month, may get underway at midnight Thursday night, but its cool temps won’t be evident evident in its opening few weeks is current forecast trends hold. That’s a period predicted to see ABOVE NORMAL TEMPS.

In fact, while last week—with its blistering mid-week heat, including last Thursday’s 100-deg record typing high—finished nearly 7-deg above normal—this week is to finish a statistical “wash” temperature wise—then see temps TAKE OFF—–with next week likely to average 10-deg warmer than this week and finish 12-deg ABOVE NORMAL. That’s a big change!

Beyond the scattered showers which have dotted the area Tuesday afternoon—rain ends this evening and DRY WEATHER IS TO HOLD through mid next week.  The LABOR DAY WEEKEND LOOKS DRY!!

And the weekend heat is to arrive with elevated humidities—-at least not right away.  That means that while daytime highs are to reach toward 96 Sat and 97 Sunday, it’s Monday and Tuesday and the mid to upper 90s predicted then which is to grow more humid.

IN THE GULF OF MEXICO—Hurricane  Idalia is undergoing its long predicted RAPID INTENSIFICATION.  The storms sustained winds, which started the day off at 70 mph, are to reach 100 mph imminently—and the abnormally warm GULF WATERS over which the storm is moving—is to take the storm toward a Wed morning landfall as a FORMIDABLE CAT 3 or possible CAT HURRICANE in Florida’s BIG BEND AREA—a region which hasn’t recorded an official landfall until now. 

There are indications the vulnerable coast there may be subject to a storm surge which could reach as high as 15 feet—a scary proposition! Forecaster in the NWS Tallahassee office aren’t mincing words. They’re imploring folks there to take this storm seriously and to get out of vulnerable areas. 



TONIGHT: Any scattered showers exit early—then cloudy spells, turning windy and cooler. Low 63 in the city and along Lake Michigan—but low to mid 50s well inland.

WEDNESDAY: Clouds break, windy and much cooler with mid to late March level temps and wind gusts approaching 30 mph along Lake Michigan. Increased sunshine is likely as clouds diminish in the afternoon and evening. High 72—-but mid to upper 70s well inland—yet only mid to upper 60s beaches.

WEDNESDAY NIGHT: Clearing with diminishing winds. Cool for the season.  Low 63 in the city—but low 50s cooler far inland locations.

THURSDAY: Sunny and calmer. Temps rebound begin to rebound in the afternoon. HIGH 77—but low 70s lakeshore.

FRIDAY: Sunny and warmer. High 86—but mid to upper 70s beaches.

SATURDAY, SUNDAY AND MONDAY: A good deal of sunshine with daytime temps growing hotter each day. Southwest winds take hold and push warmth up to and out over the Lake Michigan shoreline. Humidities remain low through Sunday but increase Monday.  High Saturday 96—with highs of 97 Sunday and Monday.

TUESDAY: Mostly sunny, hot and more humid. High 97.