A “Pneumonia Front” is on the move in the Chicago area.
Temperatures at Northerly Island dropped from 71° to 50° within about 10 minutes around 3 p.m.
And temperatures will continue to tumble.
But earlier, Thursday was the warmest day of the year so far in the Chicago area and with more cold coming up in the forecast, Chicagoans made the most of the 70s.
Many people got out doors after seven days of roller-coaster temps and wild weather that included flurries.
This was the first 70 degree day in the city since last October.