August weather forecast
South Dakota, USA

August in South Dakota can be described as a transitional month, as the intense heat of peak summer begins to wane, making way for the early hints of the forthcoming autumn season. Daytime temperatures during August generally lie between 75°F (23.9°C) and 85°F (29.4°C). While still warm, they are typically milder than the highs of July. The nights see a more pronounced dip in temperatures, ranging from 55°F (12.8°C) to 65°F (18.3°C), offering a cooler and more comfortable ambiance.

The Black Hills, due to their unique geography, continue to show slightly cooler temperatures, especially during nighttime. This makes the region an attractive spot for those looking to escape the residual summer heat.

Rainfall in August is moderate, and the frequency of thunderstorms begins to decline. However, sporadic heavy showers or even short-lived storms are not uncommon, given the changing season and atmospheric patterns. The southeastern regions still remain watchful, considering their proximity to Tornado Alley.

The transition from July to August is evident in the slightly lowered temperatures and the subtle shifts in the natural environment. Trees and vegetation start preparing for the fall, and there's a perceptible change in the air.

As August progresses, the days become noticeably shorter, and the warmth of summer gradually yields to the cooler, more temperate aura of September, which brings with it the full beauty and transformation of the autumn season in South Dakota.

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• Sioux Falls - August »
  In Sioux Falls the average relative humidity in August is 73%. In Sioux Falls, in August, during 13.2 rainfall days, 2.24" (57mm) of precipitation is typically accumulated.
• Rapid City - August »
  In Rapid City in August, during 12.8 rainfall days, 1.5" (38mm) of precipitation is typically accumulated. In Rapid City the average sunshine duration in August is 11.8h.
• Aberdeen - August »
  August and September, with an average relative humidity of 60%, are the least humid months in Aberdeen. The months with the highest UV index in Aberdeen are June through August, with an average maximum UV index of 6.
• Brookings - August »
  In Brookings in August, during 14.3 rainfall days, 2.24" (57mm) of precipitation is typically accumulated. August temperatures in Brookings vary between a high-temperature of 80.2°F (26.8°C) and a low-temperature of 59.2°F (15.1°C).
• Watertown - August »
  In Watertown, during August, the rain falls for 12.4 days and regularly aggregates up to 1.81" (46mm) of precipitation. On the first day of August in Watertown sunrise is at 6:14 am and sunset at 8:55 pm.
• Mitchell - August »
  On the first day of August in Mitchell sunrise is at 6:21 am and sunset at 8:55 pm. June through August, with an average maximum UV index of 6, are months with the highest UV index in Mitchell, South Dakota.
• Yankton - August »
  On the first day of August in Yankton sunrise is at 6:20 am and sunset at 8:50 pm. In Yankton in August, during 14.2 rainfall days, 2.24" (57mm) of precipitation is typically accumulated.
• Pierre - August »
  In Pierre in August, during 11.9 rainfall days, 1.34" (34mm) of precipitation is typically accumulated. In August, the average relative humidity in Pierre is 52%.
• Huron - August »
  In Huron during August, the rain falls for 11.6 days and regularly aggregates up to 1.97" (50mm) of precipitation. On the first day of August in Huron sunrise is at 6:20 am and sunset at 8:58 pm.
• Spearfish - August »
  The least humid month in Spearfish is August, with an average relative humidity of 49%. From the height of daytime heat, the temperature in Spearfish recedes to an average of 59.4°F (15.2°C) at night during August.
• Vermillion - August »
  As August rolls in, the peak summer heat begins to ease off in Vermillion. The average temperature in Vermillion drops to a refreshing 61.3°F (16.3°C) during the night in the month of August.
• Brandon - August »
  In Brandon during August, the rain falls for 13.1 days and regularly aggregates up to 2.13" (54mm) of precipitation. Brandon's weather in August sees a minor relief from July's heat.