Halloween is coming up on Tuesday, and it could be on the chilly side for some of those hitting the streets for trick or treating.

The National Weather Service says it’s possible that parts of Alabama could be in store for one of the coldest nights of the fall on Oct. 31 into Nov. 1 — or Tuesday night into Wednesday morning.

Alabama will have a stretch of above-average temperatures today through the weekend, but a cold front is expected to approach the state by Monday.

There will be a very small chance for rain as the front passes through, but most areas are expected to stay dry, according to forecasters.

The weather service said the big story will be the much colder air that could arrive in the wake of the front and be in place on Tuesday.

“This continental polar air mass will potentially bring our first real shot at freezing temperatures” for the northern parts of Alabama starting on Tuesday night, the weather service said.

Forecasters said there’s still some uncertainty on just how cold it could get, but temperatures in the 30s will be possible for north Alabama Halloween night into Wednesday morning.

Here are the overnight lows for Tuesday night into Wednesday morning:

More 30s will be possible for low temperatures on Wednesday night into Thursday morning for northern Alabama, forecasters said.