Keystone weather live forecast

Today's maximum temperature in Keystone is expected to be 93°F. Select a day from the live weather forecast for Keystone, South Dakota, USA for more weather parameters.

Saturday
8th Aug
93

63

12

7
Sunday
9th Aug
86

66

9

7
Monday
10th Aug
86

63

9

7
Tuesday
11th Aug
82

64

9

7
Wednesday
12th Aug
77

59

7

7

5-day weather forecast updated at 04:03 on Saturday 8th August 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 8th August 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 93°F, high levels of heat & humidity, maximum UV of 7 (High) and 12 hours of bright sunshine. There are 0-2 mm of rainfall expected with 24% chance of some rain and a light breeze of 6 mph from the south-west.

93
°F maximum temperature
63
°F minimum temperature
isolated thunderstorms
12
hours of sunshine
7
UV index (High)
24
% chance of some rain
<2
mm of rainfall expected
H
high heat & humidity
6
mph wind from SW

Keystone weather for Sunday 9th August 2026

Expect scattered clouds in Keystone, South Dakota with a maximum temperature of 86°F, moderate levels of heat & humidity, maximum UV of 7 (High) and 9 hours of bright sunshine. There are 0 mm of rainfall expected and a gentle breeze of 8 mph from the east.

86
°F maximum temperature
66
°F minimum temperature
scattered clouds
9
hours of sunshine
7
UV index (High)
0
mm of rainfall expected
M
moderate heat & humidity
8
mph wind from E

Keystone weather for Monday 10th August 2026

86
°F maximum temperature
63
°F minimum temperature
scattered clouds
9
hours of sunshine
7
UV index (High)
0
mm of rainfall expected
M
moderate heat & humidity
7
mph wind from SE

Keystone weather for Tuesday 11th August 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 82°F, low levels of heat & humidity, maximum UV of 7 (High) and 9 hours of bright sunshine. There are 2-5 mm of rainfall expected with 33% chance of some rain and a light breeze of 7 mph from the east.

82
°F maximum temperature
64
°F minimum temperature
isolated thunderstorms
9
hours of sunshine
7
UV index (High)
33
% chance of some rain
<5
mm of rainfall expected
L
low heat & humidity
7
mph wind from E

Keystone weather for Wednesday 12th August 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 77°F, maximum UV of 7 (High) and 7 hours of bright sunshine. There are 5-10 mm of rainfall expected with 64% chance of some rain and a light breeze of 7 mph from the south-east.