More than a month before the season officially begins, Suffolk will get a blast of winter temperatures this week, as a mass of Arctic air pushes into the south.

Temperatures will plunge into the low 20s Tuesday before slowly warming back into the 70s by the beginning of next week, according to John McGee, a meteorologist with the National Weather Service in Wakefield.

A cold front Monday evening was expected to herald frigid temperatures brought on by an ensuing “major dip” in the jet stream that would allow Arctic air normally trapped in Canada to encroach deep into the United States, McGee said Monday.

“We’re not really getting back to normal until Sunday or Monday,” he said.

Normal highs for this time of year in Suffolk are around 60 degrees, he said, but the high temperatures on Tuesday and Wednesday are not expected to rise out of the 30s. Nighttime lows are expected to fall to around 20 degrees Tuesday night and 27 degrees Wednesday night.

Temperatures, he said, “will start to moderate” on Thursday, and by Monday, the afternoon high is expected to reach 72 degrees.

The wintry blast should be confined to the temperature, McGee said, as Monday’s rain is the last expected until Sunday, when forecasters are predicting a 50-percent chance of precipitation. By then, temperatures are expected to be back in the 60s, with a low of about 54.

The weather service keeps no historical temperature records for Suffolk, but McGee said the record low temperature for Norfolk for Nov. 18 — set in 1959 — is 25 degrees.