It’s probably worth taking note of NOAA’s monthly climate summary for the U.S. Here is the summary for May, passed along without comment:
The average temperature in May 2009 was 62.5 F. This was 1.4 F warmer than the 1901-2000 (20th century) average, the 24th warmest May in 115 years. The temperature trend for the period of record (1895 to present) is 0.1 degrees Fahrenheit per decade.
3.22 inches of precipitation fell in May. This was 0.35 inches more than the 1901-2000 average, the 22nd wettest such month on record. The precipitation trend for the period of record (1895 to present) is 0.01 inches per decade.