The cold front came through the Chicago area from the west, about on time last night – hitting westernmost locations along the I-39 corridor just before midnight and finally passing off to the east into Indiana between 2 and 3AM this morning. Ahead of the front, riding SW winds, temps peaked in the upper 40s and lower 50s, then fell quickly after the frontal passage with winds shifting to the west-northwest. Strongest wind gusts occurred shortly after frontal passage – you may have been aroused about that time as gusts hit 45 to 50 mph at several observing sites.

Temperatures were still falling between 7 and 8AM this morning – generally running in the teens to lower 20s, while wind chills were mostly single digits. Lowest temps and coldest wind chills were along and west of Interstate-39 and the Fox River Valley. Checking area airport locations, low temp was 17-deg at Freeport and Sterling/Rock Falls with 18 at Rockford, DeKalb, and Rochelle. Coldest wind chills of -1 were also in the same area. Peak wind gusts of 51 mph were recorded at Aurora/Sugar Grove and Du Page/West Chicago – O’Hare hit 47 mph and Midway clocked a peak gust of 43 mph.

Following is a list of area airport observations of Low temp/coldest wind chill and peak gust in that order:
Aurora/Sugar Grove…20/ 4 /gust 51
Morris/Washburn…21/ 4 / gust 43
DeKalb…18/ -1 / gust 43
Du Page/West Chicago…21/ 6 / gust 51
Freeport…17/ -1 / gust 38
Lansing…24 / 7 / gust 39
Kankakee…22 /7 / gust 44
Joliet…23 /11 / gust 35
Romeoville/Lewis Univ…21 / 8 / gust 40
Midway…23 / 10 / gust 43
O’Hare…23 / 10 / gust 47
Pontiac…21 / 5 / gust 44
Palwaukee/Wheeling….24 / 10 / gust 44
Rockford….18 / 3 / gust 44
Rochelle…18 / 1 / gust 39
Sterling/Rock Falls…17 / -1 / gust 45
Waukegan…25 / 6 / gust 44
Peru/Ottawa…19 / 2 /gust 48NW Indiana
Gary…25 / 10 / gust 36
Rensselaer…30 / 17 / gust 46
Valparaiso…26 / 12 / gust 48

SE Wisconsin
Burlington/Lake Geneva…22 / 8 / gust 33
Kenosha…25 / 10 / gust 41
Janesville…19 / 5 / gust 36