At a Glance

This prolonged period of bitterly cold temperatures is setting numerous records across the central and eastern U.S.In parts of the Northeast, the coldest temperatures are yet to come.A brief break from the Arctic cold is coming, and it will provide some relief.

A long-lived Arctic outbreak has brought dangerously cold conditions to much of the central and eastern United States sinceChristmastime and will continue through this week.

This prolonged cold spell has already been notable for several reasons, including its severity, duration and widespread impacts. Wind chill warnings and advisories stretched from the on Tuesday morning – not something you see every day, as the National Weather Service office in Sioux Falls, South Dakota, pointed out.

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Here are four things to know about the bitterly cold temperatures that have taken hold across much of the U.S.

1. The Longevity of the Cold Outbreak May Break Records

A notable aspect of this Arctic cold outbreak is how long it is impacting the country. Some locations are even close to setting records for length of time below certain temperature thresholds.

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One of those places is New York City, which has not seen temperatures rise above freezingsince Christmas Day. Current forecasts indicate that the thermometer will not see a reading higher than 32 degrees until Monday, which would make for a 13-day stretch. This would tie for third place for the number of days in a row remaining at 32 degrees or colder.

The last day Boston recorded a temperature above 20 degrees was on Dec. 26. Consequently, Boston for most consecutive days with temperatures at or below 20 degreeson Tuesday. The previous record of seven days was set 100 years ago, from Dec. 29, 1917, to Jan. 4, 1918.

Chicago may also tie the record for . The current record is 12 days, set in 1936 and 1895, which would be reached on Saturday.

While not a record, it is also noteworthy how long some locations were below zero. Bismarck, North Dakota, from the morning of Dec. 29 to the morning of Jan. 2.

2. Coldest Temperatures are Still Ahead in Parts of Northeast

The cold conditions have already set numerous daily record lows and record-cold high temperatures, but in many locations in the Northeast, the coldest temperatures are yet to come.

An area of low pressure is expected to quickly intensify as it moves up the East Coast, bringing snow, ice and wind from the Southeast coast into eastern New England midweek. Behind this system, another Arctic blast will spread eastward late this week and into the weekend.

This next round of bitterly cold conditions is expected to bring the coldest temperatures yet to many locations in the Northeast.

The lowest temperature recorded in Boston so far this season was 0 degrees on Jan. 1, and temperatures are expected to plunge below zero this weekend.

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In WashingtonD.C., the coldest temperature so far has been 13 degrees on New Year's Day, Jan. 2 and Jan. 3, but lows in the single-digits are anticipated both Saturday and Sunday mornings.

3. How Cold Has it Been?

Areas from the Plains to the East Coast have been dealing with the brutal cold, but, unsurprisingly, locations in the Dakotas and Minnesota have seen the worst of it.

The coldest wind chill observed, as of early Tuesday morning, was,which occurredSunday morning.

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Hettinger also has recorded the lowest temperature so far – minus 45 on Mondaymorning. A low of minus 45was also recorded in Embarrass, Minnesota, on Sunday morning.

Sioux City, Iowa, set an impressive record – a new daily record low temperature of minus 28was setJan. 2. This ties for Sioux City's fifth-coldest temperature on recordand the coldest temperature since Jan. 21, 1970, when the low dropped to minus 26.

Also notable is that several locations set a record for the coldest final week of the year, Dec. 25-31. This includes , and . Chicago experienced its second-coldest Christmas to New Year's Eve week, with 1983 remaining in the coldest spot.

4. How Long Will Bitter Cold Last?

There is some relief ahead from the bitterly cold conditionsthat have prevailed across the central and eastern U.S.

Arctic high pressure is expected to slide off the East Coastas a low-pressure system pushes eastward this weekend into early next week. Ahead of this system, southerly flow will allow warmer temperatures to spread northward.

Temperatures in the Plains will begin to moderate by this weekend, with above-average conditions expectedSaturday or Sunday. Locations as far north as North Dakota will see temperatures rise above the freezing mark.

Warmer temperatures will also start to spread into the South and East Sunday into Monday. Areas from Texas to New England will experience high temperatures near to slightly above average on Monday. Temperatures will climb into the 30s from Boston to New York, with 40sfrom WashingtonD.C. to Atlanta early next week.

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However, this break from the Arctic cold is not currently anticipated to last long. Another round of colder-than-average temperatures is expected to dive into the northern Plains and upper Midwest midweek.