last September and was the highest since 6.07 in April 2010.
Every month in the last 13, except December, has now had more heat records than cold records. The cumulative ratio since January 2010 is 2.07. Thanks to the near-parity of records in January and February, the ratio for 2011 to date is only 1.47, but that is well ahead of the pace through the first quarter of last year.
Preliminary data through March 30 from NOAA show that the month was above average over much of the U.S., with the exception of the Pacific Northwest and the Northern Plains.
Images (click to enlarge):
- Monthly total number of daily high temperature, low temperature, and high minimum temperature records set in the U.S. for October 2010 through March 2011, data from NOAA National Climatic Data Center, background image © Kevin Ambrose (www.weatherbook.com). Includes historical daily observations archived in NCDC's Cooperative Summary of the Day data set and preliminary reports from Cooperative Observers and First Order National Weather Service stations. All stations have a Period of Record of at least 30 years.
- Cumulative excess of heat records vs. cold records by month for 2010 and 2011 to date, data source as above
- Preliminary March 2011 monthly temperature departure from climatological average from NOAA/NCEP via ESRL