Sure it's cold, but how does it stack up historically?

Temperatures throughout the Chicago suburbs dipped to their lowest levels in almost a year early Wednesday, but the subzero weather is still warmer than the Chicago area has seen on its worst days.

Thermometers at Chicago's O'Hare International Airport, the area's official climate site, recorded a temperature of 5 degrees below zero just before 7 a.m. Wednesday. The last time it was that cold was early February of last year, meteorologists at the National Weather Service office in Romeoville said.

The wind chill at O'Hare dropped to minus 18 earlier in the morning, according to the agency's weather.gov website.

Mid- to late January is typically cold for the Chicago area because of the angle of the sun this time of year, meteorologist Kevin Doom said,

"And we don't get as much direct sunlight or as much sunshine during the day," he said.

That helps make January traditionally the coldest month of the year for the area. The average temperature is 25.2 degrees, according to weather service data collected since 1873.

In fact, the three coldest temperatures ever recorded in Chicago all happened in January, weather agency records show.

Temperatures dropped to 27 below zero Jan. 20, 1985. It was 26 below zero on Jan. 10, 1982. And minus 25 on Jan. 16, 1982.

It was also 25 below zero on Christmas Eve 1983, according to records.

Wednesday's low is the seventh coldest reading for a Jan. 26 in the 150 years of record-keeping in Chicago, Doom said.

The clear skies overnight helped facilitate the colder than average temperatures that were pushed into the area by winds from the northwest. Without cloud cover, the surface warmth escapes into the atmosphere, he said.

In the suburbs, temperatures got to 5 below zero at Chicago Executive Airport in Wheeling. But it got down to minus 16 at the DuPage Airport in West Chicago and 20 below zero at the Aurora Municipal Airport in Sugar Grove.

"We get this question a lot about why it's always so much colder in Aurora," Doom said. "It's because the airport is down in this valley that's kind of shaped like a bowl, so because cold air sinks, it rolls down that valley to the airport, making readings there a little bit colder."

Many towns have opened warming centers for those seeking shelter from the cold, and many libraries and community buildings serve that purpose during extreme winter weather events.

Commuters Wednesday also found their morning routine slightly altered by the frigid temperatures, with cars taking longer to warm up and frost a little tougher to scrape off windshields.

"Whatever degrees below zero is not enough degrees," laughed Erin Shelton of Chicago as she cleaned off her car at the Elgin train station.

The area gets a warmup on Thursday with highs expected in the lower 30s. But that respite is short-lived as more cold air moves into the area Thursday night, with temperatures expected to drop to zero and a chance of snow showers Friday. Lows Friday could once again drop below zero, forecasts show.

The area might see several days of highs above the freezing mark in the middle of next week, according to the extended forecast.

• Daily Herald photographer Brian Hill contributed to this report.