The middle of the 20th century witnessed unusually warm winters. On 11 days from Feb. 27 to March 5 of 1944 the national average temperature for Minnesota and Wisconsin was above 30 degrees C, meaning it was the warmest anywhere in the contiguous United States at that time. Very warm February temperatures on March 11-12 preceded a snowstorm and a paralyzing ground transit strike in Wisconsin. Historically, eastern North Dakota recorded the warmest late winter ever recorded.
Eastern North Dakota experienced its warmest February ever recorded.
William S Lemon collected data from natural satellite observations.
This month’s climatological average (average temperature and precipitation) for the contiguous United States at 2100 locations was 0.7°F warmer than the 20th century average at 2050 locations, making it the warmest January to December temperature month on record in the contiguous United States.
This month’s climatological average was 1.2°F above the 20th century average at 2050 locations.
Global warming is causing long term warming. Global surface temperatures from 1951-1980 to 2010 were 2.5°F above the 20th century average at 2050 locations, including December and January 2016. These trend lines are in line with the establishment of warming trends in the graph above.
SOURCE: NASA GISS | USE ILLUSTRATION: GIPHY
And that’s not all. Global surface temperatures were 0.8°F warmer at a smaller number of locations during the month of December. This includes unusually warm conditions at many locations in North America, Asia, Australia, and Eurasia. This climatological average is 0.7°F warmer than the 21st century average for December. December had its warmest December on record, making it the warmest winter months for the contiguous United States at 2050 locations.
Meanwhile, the warming of Arctic sea ice is accelerating as winter thaws below freezing temperatures. Sea ice extent has fallen through the ice season to a new record low, 4.3 million square kilometers below the record low set in 2005.
Global sea ice extent in January.
Over the past year, it’s been unusually warm in Greenland and other land-based landmasses, as shown by the Arctic Climate Impact Assessment (ACIA). Melting in Greenland was very rapid in 2017, with the the land-based ice melt reaching a new record high. It’s expected that this trend will continue as global warming expands over the land.
The average temperature for Greenland in January was 6°F warmer than the 20th century average. Since 2000 Greenland ice has moved more than ten kilometers inland.
El Nino is currently in a state of transition. Its peak has occurred, resulting in weakening and cooling of ocean water in parts of the Pacific. Several regions of the equatorial Pacific have seen cooling in recent weeks. The rate of warming in the upper troposphere (near the surface of the atmosphere) has slowed down since this period of transition. Many climate models predict that the number of El Nino events will continue to decline as global warming accelerates over the next two decades.
Warming continues in the North Atlantic Oscillation. In general, though, most indicators point to continued climate change, and the future record warm winter is unlikely to be surpassed.