A blast of frigid Arctic air hit the United States late last week, causing sharp temperature drops across the country and serious traffic chaos. Between December 16 and 17, at least three low-temperature records were broken from California to Colorado and Massachusetts.
An Arctic front combined with a storm flowing across the Rocky Mountains on Friday, December 16, 2016, prompting school closings and officials to warn residents to cover up or stay indoors.
With -16 °C (4 °F), Boston woke up to coldest December 16 since 1883 when their weather stations measured -17 °C (1 °F), according to the National Weather Service.
"We definitely have a blast of Arctic air," said Lenore Correia, a meteorologist with the NWS in Taunton, Massachusetts, just outside Boston. "We have a really strong northern flow of air and it's pulling cold air down from Canada to New England and much of the country."
Wind chill and winter storm warnings were in effect for much of the northern United States - as far west as Montana and Idaho through the Midwest to New York, Massachusetts and Maine.
But Boston was not the only city with record lows last week. With -26 °C (-15 °F) on December 17, Denver broke its previous record of -25 °C (-13 °F) set in 1909. The coldest high temperatures for December 17 is -16 °C (3 °F), breaking the previous record of -13.9 °C (7 °F), last set in 1884.
In Southern California, a record low temperature of -8.8 °C (16 °F) was set at Lancaster Airport on Sunday morning, December 18, breaking the previous record of -8.3 °C (17 °F) set in 1995.
At Santa Maria Airport, a record low temperature of -2.7 °C (27 °F) was set on the same day, breaking the previous record of -2.2 °C (28 °F) degrees set in 1928.
Featured image credit: Ryan Knapp