Keystone weather in August 2025

Expect 82°F daytime maximum temperatures in the shade with on average 10 hours of sunshine per day in Keystone in August. Check more long-term weather averages for Keystone in August before you book your next holiday to South Dakota in 2025/2026.

  • 82°F maximum daytime temperature in August in Keystone82
    82°F max day temperature
  • 10 hours of sunshine per day
  • 8 days with some rainfall in August in Keystone8
    8 days with some rainfall
  • 54°F minimum night-time temperature in August in Keystone54
    54°F min night temperature
  • 14 hours of daylight per day in August in Keystone14
    14 hours of daylight per day
  • Low heat & humidity in August in KeystoneL
    Low heat & humidity
  • 1.7 inches monthly rainfall in August in Keystone1.7
    1.7 inches of monthly rainfall
  • UV (maximum) index 8 (Very High) in August in Keystone8
    8 (Very High) UV index

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The August weather guide for South Dakota (Keystone) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

Metric (°C)  |  Imperial (°F)

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How hot is it in Keystone in August?

Daytime temperatures usually reach 82°F in Keystone in August with low heat and humidity, falling to 54°F at night.

How sunny is it in Keystone in August?

There are normally 10 hours of bright sunshine each day in Keystone in August - that's 73% of daylight hours.

Does it rain in Keystone in August?

There are usually 8 days with some rain in Keystone in August and the average monthly rainfall is 1.7 inches.

Keystone August sunrise & sunset times

Browse the sunrise and sunset times for Keystone in August 2025. Select a month to view Keystone sunrise and sunset times for the next 12 months.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Friday, 1st August 2025 04:43 19:17
Saturday, 16th August 2025 04:59 18:56
Sunday, 31st August 2025 05:16 18:31

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