Keystone weather live forecast

Today's maximum temperature in Keystone is expected to be 77°F. Select a day from the live weather forecast for Keystone, South Dakota, USA for more weather parameters.

Saturday
22nd Aug
77

63

4

7
Sunday
23rd Aug
86

64

9

7
Monday
24th Aug
86

64

10

6
Tuesday
25th Aug
77

61

8

6
Wednesday
26th Aug
79

59

9

8

5-day weather forecast updated at 04:03 on Saturday 22nd August 2026 GMT

More about Keystone

Keystone by month

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Recommended for South Dakota

Intrepid Travel discount code: £200 off small group tours

Discount Code

Save EXTRA £200 on select small group tours worldwide
Min spend of £1,500 per person. T&Cs apply
Travel before 30th June 2027 (inclusive)

Show discount code

******011

Redeem Intrepid Travel discount code >>

Expires at 23:59 on Monday 31st Aug 2026 · View all Intrepid Travel offers

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 22nd August 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 77°F, maximum UV of 7 (High) and 4 hours of bright sunshine. There are 0-2 mm of rainfall expected with 31% chance of some rain and a light breeze of 7 mph from the south-east.

77
°F maximum temperature
63
°F minimum temperature
isolated thunderstorms
4
hours of sunshine
7
UV index (High)
31
% chance of some rain
<2
mm of rainfall expected
0
no heat & humidity
7
mph wind from SE

Keystone weather for Sunday 23rd August 2026

Expect isolated thunderstorms 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 2-5 mm of rainfall expected with 66% chance of some rain and a light breeze of 4 mph from the south.

86
°F maximum temperature
64
°F minimum temperature
isolated thunderstorms
9
hours of sunshine
7
UV index (High)
66
% chance of some rain
<5
mm of rainfall expected
M
moderate heat & humidity
4
mph wind from S

Keystone weather for Monday 24th August 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 86°F, moderate levels of heat & humidity, maximum UV of 6 (High) and 10 hours of bright sunshine. There are 2-5 mm of rainfall expected with 55% chance of some rain and a light breeze of 5 mph from the west.

86
°F maximum temperature
64
°F minimum temperature
isolated thunderstorms
10
hours of sunshine
6
UV index (High)
55
% chance of some rain
<5
mm of rainfall expected
M
moderate heat & humidity
5
mph wind from W

Keystone weather for Tuesday 25th August 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 77°F, maximum UV of 6 (High) and 8 hours of bright sunshine. There are 2-5 mm of rainfall expected with 52% chance of some rain and little or no wind of 4 mph from the west.

77
°F maximum temperature
61
°F minimum temperature
isolated thunderstorms
8
hours of sunshine
6
UV index (High)
52
% chance of some rain
<5
mm of rainfall expected
77
°F wind chill
4
mph wind from W

Keystone weather for Wednesday 26th August 2026

Expect isolated thunderstorms in Keystone, South Dakota with a maximum temperature of 79°F, maximum UV of 8 (Very High) and 9 hours of bright sunshine. There are 0-2 mm of rainfall expected with 58% chance of some rain and a light breeze of 5 mph from the south-east.