Rockford, Mundelein, Barrington break all-time cold records

The Polar Vortex sent temperatures plummeting to all-time lows in Rockford, Barrington and Mundelein on Thursday, but it failed to break records in other suburbs that endured the last morning of a brutal arctic blast that will subside by the weekend.

The day's low temperature in Rockford plunged to minus 31 degrees, breaking a record that had stood for 37 years, National Weather Service meteorologist Amy Seeley said. The previous all-time low of minus 27 was set there on Jan. 10, 1982. The weather service has recorded temperatures in the state's third-largest city since 1905.

For the second consecutive day, Mundelein set a record, with the mercury dropping to minus 26 at 7 a.m. The previous record was established Wednesday with a low of minus 25, and before that with a low of minus 22 on Jan. 16, 2009, weather service meteorologist Charles Mott said.

Thursday's low of minus 28 in Barrington bested a record of 26 degrees below zero set Jan. 20, 1985, Mott said.

At O'Hare International Airport Thursday morning, the official temperature — 21 degrees below zero — didn't come close to Chicago's record low of minus 27. But it did shatter the record for the coldest Jan. 31, set in 1985 when the temperature fell to minus 12, according to the weather service.

In Mt. Carroll, about 40 miles southeast of Galena, a weather observer for a National Oceanic and Atmospheric Administration cooperative reported a temperature of minus 38 degrees Thursday morning. A committee of state and federal climate experts are now reviewing whether that's the lowest temperature ever recorded in Illinois. The current record, set in Congerville about 25 miles east of Peoria on Jan. 5, 1999, stands at 36 degrees below zero, according to the weather service.

“The temperature in Mt. Carroll may be a new state record, if officially confirmed,” Illinois State Climatologist spokesman Brian Kerschner said in a statement.

Temperatures fell short of making history elsewhere partly because “a fairly narrow band” of dangerous cold was followed by a warmup that began Thursday, Mott said.

“Temperatures are rising quickly,” he said.