Sub-zero chill much of the area Tuesday night

Temperatures have plumetted to January levels in the past week. The opening five days of December have averaged nearly 20° below normal and rank ninth coldest of all such periods on record in the past 135 years. The chill has forced area residents to increase home heating 80%.
Tuesday marks the seventh consecutive day to remain below freezing and easily the coldest yet. With a high of just 12° predicted at O’Hare, the record for coldest daytime high on Dec. 6 (16° in 1893) is in jeopardy. Only two days all of last winter were as cold.
Nighttime readings will drop below zero over much of the metro area Tuesday night. A chill of that intensity usually doesn’t arrive here until the final days of December or early January.
The cold air broke records in Chicago Monday morning with lows of 4° at O’Hare and 6° at Midway. Records occurred in at least 20 other locations across 4 states.