NOAA clarifies that May 1 - 31, 2015 was wettest month on record for United States (ended drought in Southern Plains States)

May was wettest month on record for contiguous US

Devastating floods end multiyear drought in Southern Plains

The May contiguous U.S. average temperature was 60.8°F, 0.6°F above the 20^th century average, near the median value in the 121-year record. Much of the East Coast and Northwest were warmer than average, particularly the Northeast where four states were record warm. Below-average temperatures were observed across the central U.S. The spring (March-May) contiguous U.S average temperature was 53.2°F, 2.2°F above the 20^th century average, and the 11^th warmest on record.
The May precipitation total for the contiguous U.S. was 4.36 inches, 1.45 inches above average. This was the wettest May on record, and the wettest month of any month, in the 121-years of record keeping. For the spring season, the contiguous U.S. precipitation total was 9.33 inches, 1.39 inches above average, and the 11^th wettest on record.
This analysis of U.S. temperature and precipitation is based on data back to January 1895, resulting in 121 years of data.

http://www.ncdc.noaa.gov/sotc/summary-info/national/201505