The most pleasant months of the year for Plato are June, September and August. In Plato, there are 4 comfortable months with high temperatures in the range of 70-85°. July is the hottest month for Plato with an average high temperature of 84.7°, which ranks it as about average compared to other places in South Dakota. March is the snowiest month in Plato with 6.9 inches of snow, and 6 months of the year have significant snowfall. But there some days when the humidity becomes unpleasant, especially in July and August.