National Weather Service Weather Forecast Office

 May continued the string of below normal temperatures for much of central and northeast South Dakota as well as west central Minnesota.  Monthly temperatures for May ranged from just below normal at Watertown to almost 5 degrees below normal at Wheaton.  May was also below normal for precipitation at all locations across the region, making this the second consecutive month.  The monthly precipitation amounts were generally from one inch to as much as two and a half inches below normal.  Mobridge was the closest to their normal precipitation, but was still almost an inch below normal.  Aberdeen, Pierre, and Kennebec were all more than two inches below normal.

May was fairly quiet with regards to significant weather.  A storm system moved across central South Dakota on May 8^th and produced the best rainfall of the month for several locations. Rainfall amounts ranged from a half inch in Pierre and Timber Lake to over three-quarters of an inch in Mobridge.  This same area would see strong to severe storms four days later on May 12^th.   Hail, up to the size of quarters, and strong winds exceeding 60 mph were observed with the severe storms.

Cool Canadian high pressure settled over the area on May 16^th and brought much below normal temperatures.  A few locations either tied or set record lows for this date.  The low of 29 degrees in Pierre broke their previous record of 35 degrees set back in 2002.  The cold air did not last long however, as warm air would return by the 18^th.  On May 19^th, temperatures soared into the low to mid 90s across the area, making this day the warmest of the month for many locations.  Aberdeen and Sisseton both reached 96 degrees, making this the warmest day of the year.  Watertown reached a high of 94 degrees, setting a new record.  The previous record high was 93 degrees set in 1934.