Average monthly snow and rainfall in Keystone (SD)
The mean monthly precipitation over the year in Keystone (South Dakota), including rain, snow, hail.
- Most rainfall (rainy season) is seen in May.
- Keystone has dry periods in January, February, November and December.
- On average, May is the wettest month with 114 mm of precipitation.
- On average, January is the driest month with 8 mm of precipitation.
- The average amount of annual precipitation is 535 mm.
Forecast for Keystone (SD)
Fri May 17
25°C | 10°C
W 
22 km/h
22 km/h
almost clear and no rain
Sat May 18
19°C | 6°C
NW 14 km/h
14 km/h
clear and no rain
Sun May 19
24°C | 9°C
N 14 km/h
14 km/h1.4 mm
partly cloudy and thunder
