Since the records maintained from 1880 the weather from last december till febraury is recorded to be the warmest winter.
A record-warm January was responsible for pushing up the combined winter temperature, according to the agency's Web site,
http://www.noaa.gov.
In the same record 2004 takes the next warmest winter and then 1998 takes the place.
Global temperature on land surface during the northern hemisphere winter was also the warmest on record, while the ocean-surface temperature tied for second warmest after the winter of 1997-98.
