Image (click to enlarge): April 1-7, 2010 average temperature in Washington, DC vs. 10 warmest Aprils since 1871; CapitalClimate chart from National Weather Service data, background image © Kevin Ambrose
National Weather Service data confirm that Washington's summer-like heat in the first week of April was unprecedented in 140 years of records dating back to 1871. Steve Zubrick of the NWS office in Sterling, VA has reported to CapitalClimate that the April 1-7 average temperature not only exceeded the modern record in 1981 by over 4°, but it also surpassed by over 2° the 65.4° average in the very warm early April of 1929. (The daily record highs of 94° and 93° on the 7th and 8th in 1929 still stand. Temperatures cooled considerably later in the month, however, and 1929 ended with an average of 57.6°, which is now only the 29th warmest April.)
In the records of Dulles Airport dating back only to 1962, this year's April 1-7 average of 67.7° smashed by over 7° the previous record of 60.4° in 1988.
It was also the warmest first week of April in Baltimore.
For detailed data, see the previous posts:
Global Day of Overshoot
10 months ago