Keystone weather live forecast

Today's maximum temperature in Keystone is expected to be 66°F. Select a day from the live weather forecast for Keystone, South Dakota, USA for more weather parameters.

Saturday
23rd May
66

43

9

UV6
Sunday
24th May
77

48

7

UV8
Monday
25th May
84

55

14

UV8
Tuesday
26th May
82

61

12

UV8
Wednesday
27th May
73

59

9

UV7

5-day weather forecast updated at 04:02 on Saturday 23rd May 2026 GMT

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The 5-day weather forecast for South Dakota (Keystone) is provided by the Swiss meteorological agency, meteoblue. Find out more about our data sources.

Keystone weather forecast by day

Below are the detailed weather forecasts for Keystone for the next 5 days.

Keystone weather for Saturday 23rd May 2026

Expect scattered clouds in Keystone, South Dakota with a maximum temperature of 66°F, maximum UV of 6 (High) and 9 hours of bright sunshine. There are 0 mm of rainfall expected and a light breeze of 4 mph from the west.

66
°F maximum temperature
43
°F minimum temperature
scattered clouds
9
hours of sunshine
UV6
UV index (High)
0
mm of rainfall expected
66
°F wind chill
4
mph wind from W

Keystone weather for Sunday 24th May 2026

Expect sunshine and showers in Keystone, South Dakota with a maximum temperature of 77°F, maximum UV of 8 (Very High) and 7 hours of bright sunshine. There are 0-2 mm of rainfall expected with 12% chance of some rain and a light breeze of 5 mph from the west.

77
°F maximum temperature
48
°F minimum temperature
sunshine and showers
7
hours of sunshine
UV8
UV index (Very High)
12
% chance of some rain
<2
mm of rainfall expected
77
°F wind chill
5
mph wind from W

Keystone weather for Monday 25th May 2026

Expect clear skies in Keystone, South Dakota with a maximum temperature of 84°F, low levels of heat & humidity, maximum UV of 8 (Very High) and 14 hours of bright sunshine. There are 0 mm of rainfall expected and a light breeze of 7 mph from the south-east.

84
°F maximum temperature
55
°F minimum temperature
clear skies
14
hours of sunshine
UV8
UV index (Very High)
0
mm of rainfall expected
L
low heat & humidity
7
mph wind from SE

Keystone weather for Tuesday 26th May 2026

Expect scattered clouds in Keystone, South Dakota with a maximum temperature of 82°F, low levels of heat & humidity, maximum UV of 8 (Very High) and 12 hours of bright sunshine. There are 0 mm of rainfall expected and a moderate breeze of 14 mph from the south.

82
°F maximum temperature
61
°F minimum temperature
scattered clouds
12
hours of sunshine
UV8
UV index (Very High)
0
mm of rainfall expected
L
low heat & humidity
14
mph wind from S

Keystone weather for Wednesday 27th May 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 73°F, maximum UV of 7 (High) and 9 hours of bright sunshine. There are 0-2 mm of rainfall expected with 73% chance of some rain and a moderate breeze of 13 mph from the south-east.