Strange noises in the night? It's probably the furnace

Twin Cities residents reached an annual milestone this week, perhaps sooner than expected: the start of the heating season.

With a hot summer still a recent memory, furnaces kicked on across the metro area Monday and Tuesday nights as temperatures dropped into the 40s, well below normal. CenterPoint Energy noted a 10 to 15 percent increase in natural gas use those two nights, compared with the weekend, according to spokeswoman Becca Virden.

"It was a little cool in the house," said Robert Glidewell of Minneapolis, who said he and his wife switched on the heat when the indoor temperature reached 65. "We like to leave the windows open this time of year, but we left them open one day too long."

Opening Day of the heating season, of course, is a movable feast and not always celebrated. Indeed, it's often a battle of household wills.

Tammy Angrimson, owner of Shear Art Hair Studio in south Minneapolis, said she hasn't turned on the heat yet at her home near New London, despite a temperature Tuesday morning in the lower 30s.

"I'm the boss in my house," she said.

Jenna Kroning, her salon manager, is not the boss in her Minneapolis house, since she rents, but hasn't felt the need to ask her landlord for heat.

Kroning noted that she also survived the Twin Cities' second-warmest summer on record the old-fashioned way. "We don't have air conditioning, either," she said.

Nevertheless, Twin Cities residents are preparing for serious cold. Of the jobs scheduled through Tuesday by CenterPoint Energy for the next 10 days, 62 percent were for either tune-ups or heating jobs, compared with 52 percent a week ago, Virden noted.

Natural gas steam boilers in Minneapolis public schools started getting fired up this week, said Grant Lindberg, facilities operations manager for the school district. That's about two or more weeks earlier than normal, Lindberg said. All the schools are usually getting heat by Oct. 15.

On Sept. 11, the Twin Cities experienced a high of 95 and schools were handing out bottles of water to students.

"This little cold wave that's catching us was a little surprise," Lindberg said. Some schools well shaded by trees have been particularly cool, he said, while others simply don't retain heat well.

As expected, the core of the metro area hasn't cooled off quite as deeply as the rest of the state. Much of the northern one-third of Minnesota has seen freezing temperatures; Hibbing dropped to 25 and International Falls to 20 Tuesday morning.

Most of the southern one-third of the state has had lows between 35 and 40, according to the Minnesota DNR Climatology office. The central metro area hadn't dipped below 40 through Tuesday; the low of 43 Tuesday morning was the coldest reading since April 28. The average date of the first 32-degree reading in the Twin Cities is Oct. 7. Last year it arrived Oct. 21.

Despite the recent chill, September in the Twin Cities was running 3.8 degrees above normal through Tuesday. But the forecast is calling for below-normal temperatures Thursday through Sunday, with highs Saturday and Sunday in the mid- to upper 50s.