From NWS in Joliet:

000
NOUS43 KLOT 170129
PNSLOT

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
730 PM CDT FRI SEP 16 2011

UNSEASONABLY COOL CONDITIONS HAVE CONTINUED TODAY. THIS WAS THE
SECOND TIME IN HISTORY THAT THERE WERE 3 CONSECUTIVE DAYS WITH HIGH
TEMPERATURES UNDER 60 DEGREES THIS EARLY IN THE SEASON.  THE HIGH
TEMPERATURES FOR SEPTEMBER 14,15 AND 16 WERE 58,59, AND 60
RESPECTIVELY.  THE LAST TIME THIS HAPPENED WAS BACK IN 1923. WHEN ON
SEPTEMBER 13, 14, AND 15, THE HIGH TEMPERATURES WAS 56, 54, AND 59
RESPECTIVELY.

$$