MADISON, Wis. (January 23, 2013)--The Upper Midwest remained locked in the deep freeze, with bitter temperatures stretching into a fourth day across several states Wednesday.
The cold snap arrived Saturday night as waves of Arctic air swept south from Canada, pushing temperatures to dangerous lows and leaving a section of the country well-versed in winter's pains reeling.
Authorities think exposure was a factor in at least four deaths so far.
Among the coldest temperatures recorded Tuesday was 35 below at Crane Lake, Minn., a National Weather Service forecaster said early Wednesday.
The coldest location in the lower 48 states Monday was Embarrass, Minn., at 36 below, according to the National Weather Service.
The bitter conditions were expected to persist into the weekend in the Midwest through the eastern half of the U.S.
Boston and New York were expecting wind-chill conditions that will feel like five degrees below zero Wednesday.
Residents of Millinocket, Maine woke up to 9-degree temperatures Wednesday.