There’s nothing unusual about cold winter weather in Chicago. But, the intensity of the chill we’ve endured in recent weeks is quite unusual for this early in a new cold season. The opening 19 days of the month have averaged 18.4° making it the fourth coldest December open since 1870. It’s a temperature 14.3° below a comparable period one year ago and only 1.3° away from than the coldest Dec. 1-19 period on the books in the city: 17.1° in 1958. Monday’s 11° high was the coldest December daytime temperature in 5 years. Only 46 December days have been as cold or colder since 1870.
The area’s first official sub-0° low of the season occurred at 8:30 a.m. Monday when O’Hare’s readings reached -1°. West suburban DeKalb and Rochelle hosted the area’s coldest lows of -7°.
Heating this air without adding moisture Monday produced indoor humidities of just 4-6%, a fraction the 35% considered comfortable by most.
-Tom Skilling
WGN-TV Chief Meteorologist Tom Skilling and the WGN Weather Center staff provide daily coverage of weather in the Chicago area.
