It’s a winter-like start to the week in Maine.

Temperatures were forecast to drop to near-record lows Monday night and stay unseasonably cool on Tuesday, according to the National Weather Service, with a chance of rain and even snow showers lingering throughout the week.

Most of Maine was expected to experience temperatures in the low 20s and high teens Monday night, coming within shouting distance of records for April 20.

Northern Franklin, Oxford and Somerset counties were projected to be among the coldest regions in the state Monday night, dropping to as low as 10 degrees in the Jackman area, the weather service said.

Jon Palmer, a meteorologist at the weather service’s office in Gray, said low temperatures around 24 degrees, expected in Portland on Monday night, would come close to the record for April 20 — an even 20 degrees, set in 1960.

The Lewiston, Augusta and Midcoast regions can expect temperatures in the low 20s, according to the weather service. Down East Maine was expected to be the warmest — relatively speaking — in the state Monday, with temperatures only projected to dip to the high 20s, according to the weather service’s Caribou office.

A high-pressure system with a “very deep” midlevel trough was hovering over southern Maine on Monday, Palmer said, and is to blame for the cold temperatures.

Things will begin heating back up Tuesday, but by no means quickly. Palmer said coastal areas can expect low temperatures around 32 degrees Tuesday night. Other areas can expect temperatures in the mid- to high 20s.

Things will start to warm up back toward average as the week goes on, Palmer said.

Some snowflakes fell in parts of Maine on Monday, and more could be spotted over the next few days, the weather service warned. Palmer said it’s difficult to predict where and when snow will appear.

“These shoulder season snows tend to be a bit funky,” Palmer said.

Generally, the interior part of the state stands the highest chance of seeing flakes or a wintry mix, while coastal Maine can expect more rain.

However, nothing “impressive” is expected in the way of accumulation, he said, with snow most likely melting on contact with the ground.

“It’s just kind of a lame duck April pattern,” Palmer said.

Rain and snow showers should move out of southern and central Maine after Thursday, according to the weather service office in Gray, being replaced by dry and breezy conditions Friday.