Keystone weather live forecast

Today's maximum temperature in Keystone is expected to be 25°C. Select a day from the live weather forecast for Keystone, South Dakota, USA for more weather parameters.

Tuesday
18th Aug
25

15

6

6
Wednesday
19th Aug
25

14

7

6
Thursday
20th Aug
30

15

12

8
Friday
21st Aug
28

17

7

8
Saturday
22nd Aug
27

16

10

7

5-day weather forecast updated at 04:03 on Tuesday 18th 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 Tuesday 18th August 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 25°C, maximum UV of 6 (High) and 6 hours of bright sunshine. There are 2-5 mm of rainfall expected with 74% chance of some rain and little or no wind of 6 kph from the west.

25
°C maximum temperature
15
°C minimum temperature
isolated thunderstorms
6
hours of sunshine
6
UV index (High)
74
% chance of some rain
<5
mm of rainfall expected
25
°C wind chill
6
kph wind from W

Keystone weather for Wednesday 19th August 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 25°C, maximum UV of 6 (High) and 7 hours of bright sunshine. There are 2-5 mm of rainfall expected with 37% chance of some rain and a light breeze of 7 kph from the west.

25
°C maximum temperature
14
°C minimum temperature
isolated thunderstorms
7
hours of sunshine
6
UV index (High)
37
% chance of some rain
<5
mm of rainfall expected
0
no heat & humidity
7
kph wind from W

Keystone weather for Thursday 20th August 2026

Expect clear skies in Keystone, South Dakota with a maximum temperature of 30°C, 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 light breeze of 9 kph from the west.

30
°C maximum temperature
15
°C minimum temperature
clear skies
12
hours of sunshine
8
UV index (Very High)
0
mm of rainfall expected
L
low heat & humidity
9
kph wind from W

Keystone weather for Friday 21st August 2026

Expect broken clouds in Keystone, South Dakota with a maximum temperature of 28°C, low levels of heat & humidity, maximum UV of 8 (Very High) and 7 hours of bright sunshine. There are 0 mm of rainfall expected and a light breeze of 10 kph from the north-east.

28
°C maximum temperature
17
°C minimum temperature
broken clouds
7
hours of sunshine
8
UV index (Very High)
0
mm of rainfall expected
L
low heat & humidity
10
kph wind from NE

Keystone weather for Saturday 22nd August 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 27°C, low levels of heat & humidity, maximum UV of 7 (High) and 10 hours of bright sunshine. There are 0-2 mm of rainfall expected with 23% chance of some rain and a gentle breeze of 13 kph from the south-east.