Keystone weather live forecast

Today's maximum temperature in Keystone is expected to be 63°F. Select a day from the live weather forecast for Keystone, South Dakota, USA for more weather parameters.

Saturday
19th Sep
63

54

1

2
Sunday
20th Sep
55

50

2

1
Monday
21st Sep
59

50

1

3
Tuesday
22nd Sep
68

50

6

3
Wednesday
23rd Sep
73

55

7

5

5-day weather forecast updated at 04:03 on Saturday 19th September 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 19th September 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 63°F, maximum UV of 2 (Low) and 1 hour of bright sunshine. There are 10-20 mm of rainfall expected with 87% chance of some rain and a light breeze of 5 mph from the east.

63
°F maximum temperature
54
°F minimum temperature
isolated thunderstorms
1
hour of sunshine
2
UV index (Low)
87
% chance of some rain
<20
mm of rainfall expected
63
°F wind chill
5
mph wind from E

Keystone weather for Sunday 20th September 2026

Expect mostly cloudy with rain in Keystone, South Dakota with a maximum temperature of 55°F, maximum UV of 1 (Low) and 2 hours of bright sunshine. There are 20-30 mm of rainfall expected with 100% chance of some rain and a light breeze of 5 mph from the east.

55
°F maximum temperature
50
°F minimum temperature
mostly cloudy with rain
2
hours of sunshine
1
UV index (Low)
100
% chance of some rain
<30
mm of rainfall expected
0
no heat & humidity
5
mph wind from E

Keystone weather for Monday 21st September 2026

Expect mostly cloudy with rain in Keystone, South Dakota with a maximum temperature of 59°F, maximum UV of 3 (Moderate) and 1 hour of bright sunshine. There are 5-10 mm of rainfall expected with 55% chance of some rain and a light breeze of 6 mph from the south-east.

59
°F maximum temperature
50
°F minimum temperature
mostly cloudy with rain
1
hour of sunshine
3
UV index (Moderate)
55
% chance of some rain
<10
mm of rainfall expected
59
°F wind chill
6
mph wind from SE

Keystone weather for Tuesday 22nd September 2026

Expect broken clouds in Keystone, South Dakota with a maximum temperature of 68°F, maximum UV of 3 (Moderate) and 6 hours of bright sunshine. There are 0 mm of rainfall expected and a gentle breeze of 9 mph from the south.

68
°F maximum temperature
50
°F minimum temperature
broken clouds
6
hours of sunshine
3
UV index (Moderate)
0
mm of rainfall expected
68
°F wind chill
9
mph wind from S

Keystone weather for Wednesday 23rd September 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 73°F, maximum UV of 5 (Moderate) and 7 hours of bright sunshine. There are 2-5 mm of rainfall expected with 32% chance of some rain and a light breeze of 6 mph from the south-west.