Keystone weather live forecast

Today's maximum temperature in Keystone is expected to be 19°C. Select a day from the live weather forecast for Keystone, South Dakota, USA for more weather parameters.

Thursday
17th Sep
19

14

1

3
Friday
18th Sep
22

14

6

6
Saturday
19th Sep
19

13

2

2
Sunday
20th Sep
15

11

4

2
Monday
21st Sep
17

11

9

5

5-day weather forecast updated at 04:03 on Thursday 17th 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 Thursday 17th September 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 19°C, maximum UV of 3 (Moderate) and 1 hour of bright sunshine. There are 10-20 mm of rainfall expected with 99% chance of some rain and a light breeze of 9 kph from the east.

19
°C maximum temperature
14
°C minimum temperature
isolated thunderstorms
1
hour of sunshine
3
UV index (Moderate)
99
% chance of some rain
<20
mm of rainfall expected
0
no heat & humidity
9
kph wind from E

Keystone weather for Friday 18th September 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 22°C, maximum UV of 6 (High) and 6 hours of bright sunshine. There are 2-5 mm of rainfall expected with 39% chance of some rain and a light breeze of 7 kph from the north-east.

22
°C maximum temperature
14
°C minimum temperature
isolated thunderstorms
6
hours of sunshine
6
UV index (High)
39
% chance of some rain
<5
mm of rainfall expected
0
no heat & humidity
7
kph wind from NE

Keystone weather for Saturday 19th September 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 19°C, maximum UV of 2 (Low) and 2 hours of bright sunshine. There are 5-10 mm of rainfall expected with 79% chance of some rain and a light breeze of 7 kph from the east.

19
°C maximum temperature
13
°C minimum temperature
isolated thunderstorms
2
hours of sunshine
2
UV index (Low)
79
% chance of some rain
<10
mm of rainfall expected
19
°C wind chill
7
kph wind from E

Keystone weather for Sunday 20th September 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 15°C, maximum UV of 2 (Low) and 4 hours of bright sunshine. There are 10-20 mm of rainfall expected with 92% chance of some rain and little or no wind of 6 kph from the east.

15
°C maximum temperature
11
°C minimum temperature
isolated thunderstorms
4
hours of sunshine
2
UV index (Low)
92
% chance of some rain
<20
mm of rainfall expected
15
°C wind chill
6
kph wind from E

Keystone weather for Monday 21st September 2026

Expect sunshine and showers in Keystone, South Dakota with a maximum temperature of 17°C, maximum UV of 5 (Moderate) and 9 hours of bright sunshine. There are 2-5 mm of rainfall expected with 55% chance of some rain and a light breeze of 7 kph from the south-east.