Friday's high temperatures will be about 20 degrees below average, and will fall even lower during the late-night hours. Some northern Chicago suburbs could even experience 30-degree temperatures overnight.
That means some furnaces around Chicago may be firing up for the first time this season, and it's not even mid-September. The Chicago area on Thursday set a new record for the coldest high temperature of the date.
As a matter of fact, Friday's chilly and wet conditions would be more appropriate for November 1. The afternoon high temperature is expected to be about 56 degrees with a breeze and showers or light rain.
That rain moves east and out of the area by the nighttime hours, leaving behind breezy, damp and chilly conditions. The expected temperature of about 48 degrees may be just a little too chilly for sleeping.
Saturday is expected to be another chilly day but the sun will be out as the weekend leads to a gradual warm-up in the days ahead.
For those residents who do turn on their furnaces, it's a good idea to ensure they're in good working order to avoid any problems with carbon monoxide. Detectors should have fresh batteries.
A chief symptom of carbon monoxide poisoning is a headache. Nationwide, there are about 500 deaths related to carbon monoxide poisoning each year. Another 15,000 people visit the emergency room with symptoms.