Greatest temperature fall coincides with greatest pressure rise Midnight to 8 A.M. Wednesday

Very cold high pressure building into our area behind the cold front that passed through the Chicago area Tuesday evening, and moved off to the east during the day Wednesday. Temperature dropped from 34 – degrees at Midnight to 23-degrees between 6 and 8AM…at the same time the barometric pressure rose from 29.67-inches at Midnight to 29.94-inches at 8AM. The temp then rose ever-so-slowly during the daylight hours and the rise in pressure slowed.

Wednesday’s cold temperatures combined with strong west winds giving single-digit to lower teens wind chills across the Chicago area

Wind Chills dropped into the single digits and lower teens Wednesday as cold high pressure built into the Chicago area, Temps held in the 20s area-wide, which combined with strong westerly winds gusting over 40 mph gave the very cold wind chills. The map shows a plot of coldest wind chill readings at local airport locations Wednesday – coldest was 4-degrees registered at Rochelle, DeKalb and Aurora/Sugar Grove. Highest wind gusts were 51 mph at Midway and 46 mph at Aurora/Sugar Grove and Kenosha, WI.

From Tuesday’s springlike 50s to wintry 20s Wednesday

Late afternoon Wednesday temperatures

How much colder than same period Tuesday?