Chilling Halloween forecast: Northern Illinois will be cold, chance of flurries

Trick-or-treaters likely will need their jackets Halloween night.

Temperatures are expected to be in the low 40s late afternoon, on their way to a predicted overnight low of 25 degrees, according to the National Weather Service in Chicago.

The forecast calls for partly sunny skies late in the afternoon, clearing for a cold evening.

“This will be the coldest weather we’ve seen so far this season,” said Kevin Birk, meteorologist for the National Weather Service in Chicago.

There is a 20% probability of precipitation, which could amount to some snow flurries during the later afternoon, but snow is not expected to accumulate, Birk said. Additionally, wind gusts could reach 15 mph in the evening, making the wind chill about 15 degrees.

“We’re getting into the time of season when we will see more fall systems,” Birk said. “Every now and again we will see some snow on Halloween, but rarely do we see accumulation, like we did in 2019, when I think we saw a couple of inches and set a record.”

Forecasters are encouraging trick-or-treaters to wear layers underneath their costumes, wear stocking hats and gloves, and cover exposed arms and legs.

“The biggest message I’d tell parents and trick-or-treaters is stay warm, it’s going to be a cold one,” Birk said.

The predicted low temperature will come close to a record low for Oct. 31 of 23 degrees set in 2019. The Halloween average high is 56 degrees and the average low is 38 degrees, making next Tuesday’s trick-or-treating an unusually cold one.

For anyone looking to attend other outdoor Halloween events over the week, expect wet weather Thursday and Friday. Temperatures will stay in the 60s both days.

Saturday is predicted to bring sunny skies and chillier temperatures with a predicted high of 52 degrees and a low of 41. Rain could return Sunday, with a 91% chance of wet weather. High temperatures Sunday are predicted to be in the 40s with low temperatures reaching the 20s. Monday will stay cold with a high temperature of 39 degrees forecasted and a low of 23 degrees, but sunny skies are expected, the National Weather Service said.