First frost possible Friday, warmer temps into the week

The first frost of the season was expected Friday night, the National Weather Service said, advising residents in northern Illinois to bring in their plants or cover them up.

The region was on track to see low temperatures overnight ranging from 30 to 33 degrees, said Matt Friedlein, a meteorologist at the National Weather Service’s Romeoville office.

Friday night’s expected overnight lows would be the coldest temperatures the region has seen since late April, Friedlein said.

The good news is temperatures could reach the upper 70s by Wednesday, but another cold system is expected to follow that, he said.

Friday’s lower temperatures came on the heels of a cold front that moved through Thursday afternoon, bringing shower and thunderstorms to parts of the region, Friedlein said.

The cold front, combined with little wind, create the perfect conditions for frost, he said.

“The wind will ease here [Friday night], so it won’t completely fall to calm, but down to 5 mph over the metro area with temps dropping to the lower 30s,” Friedlein said.

Between lower winds and the dropping temperatures, “it will allow frost development across the western and northwestern metro area. A lot of the suburbs will see widespread frost,” he said.

“Those lows will be in McHenry, Kane and outlying suburbs from 30 to 33” degrees overnight, Friedlein said.

Toward DuPage and Cook counties, those lows could stay in the mid-30s and low 40s and may not get to a heavy freeze, he added.

“Near the lakefront, the water is warmer right now,” as is the wind that comes off the water, he said. That and the urban “heat island” may prevent temperatures from hitting the freezing mark, Friedlein said.

But Lake, McHenry, Kane, Kendall, Will, western DuPage and northwest Cook counties “will see the frost more widespread at 30 to 31 degrees. Cold can damage plants even without frost. Just that cold can be damaging too,” Friedlein said.

He wouldn’t make a guess on when the area might see snow this year.

“It can be as early as now,” Friedlein said. “We have had traces of snow this early. But the first flurries are usually flying in first week of November.

“We are not seeing anything on the horizon – but with each cold front, we step down a little bit more” as the days get colder, he said.