"The bottom really fell out. We had temperatures in the mid 70s. Cold front rolled through and temperatures dropped about 20 degrees in one hour," said ABC7's Meteorologist Jerry Taft said Thursday. "Cold air pushed it, and it's here to stay."
The high Thursday was 75 and by 10 p.m. it was 46 degrees at O'Hare. That drop from the 70s way down into 50s came between 5 p.m. and 7 p.m.