Record U.S. warmth in March was not shared everywhere globally.

By Janet Raloff

Web edition: April 16, 2012

Even as global temperatures have been climbing throughout much of the past century, atypical warm and cool spells have seesawed regionally around the planet. March 2012 exemplified such exaggerated trends. Although the month set some 15,000 daily warming records in the United States, globally this past March was the coolest since 1999. The National Climatic Data Center reported these trend data April 16.

March’s planetary average of 13.2° Celsius still points to a steadily climbing planetary fever. That value was roughly 0.5 °C higher than the 20th century March average. And seven of the eight warmest years on record have occurred since 2001, the National Oceanic and Atmospheric Administration notes. The top 10: all since 1995.

The combined land-and-sea-surface average temperature for January through March 2012 was 0.39 °C above the 20th century average. That matched 1991 as the 21st warmest such quarter on record — and the coolest since 1996.

Polar ice rallied somewhat this year. March’s Arctic sea ice cover was the largest for this month since 2008 (and only the ninth lowest since satellite records began in 1979). In Antarctica, sea ice during March was 16 percent higher than the average and fourth largest for the month since 1979.

All of that is small comfort for me today. Normally, this time of year the temperature peaks in Washington, D.C., at a balmy 19.4 °C (67 °F). But today’s forecast calls for a blistering 30° (or 86 °F) outdoors. Even with shades drawn, the morning temperature in my sun-facing fourth floor office was distinctly uncomfortable. And without supplemental cooling (my A/C is out of service), the temp at my desk can be expected to exceed the outdoor heat by some 3° to 5°.