SD: Wettest May on record since 1895 |

SD: Wettest May on record since 1895

BROOKINGS, S.D. – Moisture during the month of May rapidly transitioned the state out of drought conditions.

"Preliminary data indicate that at least eight climate stations reported their wettest May on record, with more reports yet to come in," said Laura Edwards, SDSU Extension Climate Field Specialist.

The north central and southwest regions were among the wettest areas of the state. The north central region weather stations recorded their second wettest May since 1895 with a regional average of 6.22 inches; the other wettest was recorded in 1906 when the region-wide average was 6.73 inches.

Records were also set at individual weather stations; Mobridge recorded not only its wettest May, but May 2015 is documented in the record books as the wettest month in the location's recorded history with 9.32 inches of precipitation. This exceeds the previous record of 8.85 inches in June 1915.

Edwards added that the southwest region of the state had many climate stations that measured two to three times their average May precipitation. "As a region, the southwest also had its second wettest May on record, with an average of 7.29 inches," Edwards said. She said the wettest May for this region occurred in 1982, with a region-wide average of 7.34 inches.

Transition out of drought

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Following the driest January through April period on record for South Dakota, the May 5, 2015 U.S. Drought Monitor had 78 percent of the state in moderate to severe drought (in D1 and D2 designations.) By May 26, 2015 only 9 percent of the state was in drought, focused on the southeastern region.

The May statewide average precipitation was 5.88 inches, according to preliminary data. Monthly precipitation ranged from less than three inches to over 10 inches.

Snow was a contributor to May's moisture levels, with many western South Dakota areas, including Bison, Martin and Interior, which reported more than 10 inches of snowfall on May 10 and 11, setting several new snowfall records for the month of May.

Climate outlook

National Oceanic Atmospheric Administration (NOAA) released the June 2015 Climate Outlook which Edwards calls "a mixed bag."

"The month appears to start off warmer than average, but temperatures could turn towards average or below average by the end of the month," she said. "Overall, NOAA's Climate Prediction Center has indicated equal chances of below, above and near median temperatures for the month."

As far as precipitation for the month ahead, Edwards said there is an increased likelihood of above median precipitation across most of the state, with higher probability along the Nebraska border. "If this monthly outlook holds true, it could mean the end to our worries of drought for a while," she said.

Edwards said El Nino continues to be a factor in this season's outlook, as a moderate to strong event is currently underway. "In general, El Nino means less likelihood of long term extreme heat events and less likelihood of extended dry conditions in the summer season."

So far, Edwards said El Nino has been bountiful in bringing rain to our drought-plagued region of just four weeks ago.

–SDSU Extension