May 2015 Was the Wettest Month on Record in the Lower 48 U.S. States

Chris Dolce
Published: June 8,2015



 
May 2015 was the wettest May and the wettest month on record for the Lower 48 states dating to 1895, according to the State of the Climate report released by the National Oceanic Atmospheric Administration (NOAA) on Monday.

State-by-state precipitation rankings for May 2015. Green shades indicate above-average precipitation; orange shades, below-average precipitation. Numbers indicate the ranking among all Mays since 1895.
(NOAA)

Precipitation across the country overall averaged 4.36 inches in May 2015, which is 1.45 inches above average. This beat both the previous May record of 4.24 inches in 1957 and the previous wettest month on record of 4.29 inches in October 2009.
As weather.com reported on extensively last month, the central states were soaked by numerous bouts of record-breaking rainfall. Oklahoma and Texas were hit the hardest, and both states recorded their wettest month on record in May 2015.
(RECAP: Catastrophic Flash Flooding Texas, Oklahoma | Jaw-Dropping Houston Flood Images)
Elsewhere, NOAA says that Colorado recorded its wettest May on record, while Kansas, Louisiana and Utah all saw their second wettest May. Eight additional states recorded a top 10 wettest May, including Arizona, Minnesota, Nebraska, Nevada, New Mexico, North Dakota, South Dakota and Wyoming.
But not everyone was soaked by rainfall last month. Six states along the East Coast recorded a top 10 driest May, including Connecticut, Delaware, Massachusetts, New Jersey, Rhode Island and South Carolina. Many more states in the East saw a drier-than-average May.
When looking at the Lower 48 as a whole, the drier-than-averge conditions in the East were essentially canceled out by the expansive area of much above-average precipitation in the central states. This illustrates how excessive and widespread the rainfall amounts were in May 2015.
(MORE: Dallas-Ft. Worth Flooding May 28-29)
Here are some other notables from NOAA's May 2015 state of the climate report:

• Connecticut, Massachusetts, New Hampshire and Rhode Island all recorded their warmest May on record.
• The Northeast region as a whole recorded its warmest May on record. This follows the region's second coldest February a few months ago.
• Alaska saw its warmest May in 91 years of records.
• Florida recorded its warmest spring (March-May).
• Texas saw its wettest spring (March-May), and its wettest first five months of the year (January-May).

(MORE: Record Warm May in Northeast | Warmest Spring in Florida)