CONGERVILLE — Last week, five weather professionals joined a conference call from their respective climate-controlled offices in Champaign, Kansas City, Asheville, N.C. and Davenport, Iowa. They were enlisted to be the final arbiters of a central question that had lingered over two Illinois communities, like a stubborn blast of polar air, for the better part of a month.

Not a lot of people were awaiting their answer. The decision mattered deeply to almost no one.

Yet there it was.

Congerville or Mount Carroll?

Reigning champ, or former champ?

A farm on the banks of the Mackinaw River in Woodford County, or a water and sewer plant next to Point Rock Park in the county seat of Carroll County in northwest Illinois?

Rick Dickinson or Bill Zink?

Minus-36 degrees, or minus-38 degrees?

"We look at three things," said Ray Wolf, a meteorologist with the National Weather Service in the Quad Cities who was in on the conference call that would decide a new state cold temperature record. "Was the (temperature) reading meteorologically plausible in the context of the weather of the day; was it taken at a government-endorsed weather station that is archived, and was the observation taken on equipment that was working properly?"

The answers? Yes, yes and yes.

At 7:15 a.m. on Jan. 31, 2019, Bill Zink, the superintendent of the Mount Carroll water and sewer plant, performed his daily duty of recording the local temperatures for the National Weather Service office in the Quad Cities. He opened the shuttered door of the stilted weather station that has been out back of the plant for generations and checked the alcohol thermometer for the overnight low temperature.

Minus-38 degrees, it read.

"I knew it was going to be cold that morning," Zink said in a recent phone interview."Obviously I wasn't expecting it to be that cold."

Like he does every day, Zink logged onto his computer and tapped in the number. Unlike every other day, a box popped up on his screen.

"The number was so low, I had to verify," he said. "After I typed it back in, it didn't take real long for my phone to ring."

It was the National Weather Service calling.

The reading triggered a series of checks, counter-checks and counter-checks of the counter-checks.  The next day, Wolf drove to Mount Carroll, met with Zink, examined the thermometer and determined it to be in working order.  He then passed on the information to Brian Kerschner of the State Climate Office in Champaign, Mike Timlin of the Midwest Regional Climate Center, also in Champaign, Tim Kearns of the weather service Regional Cooperative in Kansas City and Deke Arndt, of the National Center for Environmental Information in Asheville.

If those five men agreed, the Mount Carroll reading of minus-38 degrees would become the coldest temperature ever recorded in Illinois. It would drop to second place a reading of minus-36 degrees taken in Congerville, on Jan. 5, 1999, by Rick Dickinson. He's the Woodford County farmer and weather volunteer who still to this day takes the daily readings for the National Weather Service in Lincoln. Now up for grabs, a state record would give Mount Carroll back the dubious distinction it held for 69 years as the coldest spot in Illinois — at minus-35 degrees — before Rick Dickinson recorded the minus-36 degrees in Congerville 20 years ago.

"I doubt it is something that is really going to bring the tourists in," Zink said.

The potential for record cold temperatures in the region had been predicted for a week. Schools and businesses across the Midwest closed in advance on the forecast. Then it happened as expected.

"Records fell (Jan. 31) and Feb. 1) from Minnesota to Ohio," said Bryan Peake, service climatologist with the Midwest Regional Climate Center in Champaign who has studied the polar air mass outbreak. "We saw new records set in 50 to 60 stations in a swath from southern Wisconsin to eastern Iowa to northern Illinois."

Beloit, Wis., for example, set an all-time city record of minus-27 degrees on Jan. 30, and broke it on Jan. 31 with a reading of minus-29. On Jan. 31, it fell to minus-47 degrees in Mather, Wisconsin.

The conference call with the climatologists on Feb. 21 ended with a 5-0 vote to make the minus-38 degree reading in Mount Carroll on Jan. 31, 2019, the coldest recorded in the 120-year history of recording cold temperatures in Illinois. It is not "official" however, until the paperwork is buttoned up and the press release is sent out to news organizations. That could happen next week.

"Records are fun, they're a novelty, I don't dismiss that at all," said Deke Arndt, of the National Center for Environmental Information in Asheville, who also helped verify the largest hailstone in the state and the most rainfall in a 24-hour period in the United States — a jaw-dropping 49.69 inches last April in Hawaii. "But more than that they show how big our weather can get and provides the best data we can get at the edge of what is possible. It has an impact on a wide spectrum of human activity."

A bogus record popped up 10 years ago on a popular, and presumably authoritative, Internet web site. Don't be fooled.

"It is important to note that some sources, including Wikipedia, have listed minus-37 degrees in Rochelle on Jan. 5, 2009 as the lowest temperature in Illinois," according to a service web site. "However, that observation came from a small airport station designed for aviation purposes and was not part of the climate network in Illinois. As a result, the data were not always archived and no quality control procedures were applied to the data. It was never officially recognized as the state record." 

On Thursday morning, Rick Dickinson was helping his son birth a bunch of lambs on their farm in Congerville. He checked the temperature like he does everyday and reported a humdrum low temperature in the middle-teens. No record. Not even close. Records are rare. Baby sheep happen every year.

So, is he disappointed that Congerville will no longer be listed as the site of the coldest temperature ever recorded in Illinois? Does he resent Mount Carroll's return to its frigid notoriety?

"Heavens no," he said. "They can have it."

Scott Hilyard can be reached at 686-3244 or by email at shilyard@pjstar.com. Follow @scotthilyard on Twitter.