During the spring, weather becomes very changeable with frequent severe storms: the first maximum of at least can be expected on April 17, but the last spring freeze normally does not occur until May 24. The spring is also the wettest season owing to the frequent storms, with the wettest month of May 1965 seeing of precipitation. The wettest year – and a South Dakota calendar year record – has been 2013 with and the driest 1936 with . Summers are very warm in the afternoon, but mornings are pleasantly cool: frost-level temperatures occurred in July 1921 and in the Augusts of 1910 and 1911, with August 1910 seeing a freak snowstorm of . The hottest temperature has been on July 7, 1936 during a notorious Plains heat wave. Precipitation is lower in summer than in spring, and declines further into the fall and winter as temperatures cool. Fall weather is similarly variable in temperature, as is the spring; however, the fall period tends to be less prone to severe weather.