WASHINGTON -- Federal meteorologists say this winter was the warmest in U.S. record, thanks to the combination of El Niño and man-made global warming.

The average temperature for the Lower 48 states from December through February -- the period known as meteorological winter -- was 36.8 degrees Fahrenheit, 4.6 degrees above normal. That breaks the record set in 1999-2000.

National Oceanic and Atmospheric Administration climate scientist Jake Crouch said a super-warm December -- with Christmas Day temperatures in the 60s on the East Coast -- pushed the winter to record territory. The fall of 2015 also set a U.S. record.

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All six New England states had their warmest winters. Every state in the Lower 48 was at least 1.7 degrees warmer than normal. Alaska was 10.6 degrees warmer than normal.

This record-hot winter also saw increased precipitation levels. NOAA reports that there was above-average precipitation across the Northwest, Central Plains, Midwest, and along the East Coast. Iowa hit a record with 6.2 inches, more than double its average level. Conversely, Hawaii had a dry winter, with almost all locations across the islands displaying below-average precipitation.

NOAA's analysis of U.S. temperature and precipitation shifts is determined by examining data that stretches back to January 1895.