Keystone, SD Weather Forecast

Local 7-day forecast

100°

Sunny then Slight Chance Showers And Thunderstorms

Track current conditions, temperature changes, wind, and the full daily outlook for Keystone, SD in one place.

Sunday, July 26, 2026

Wind: 6 mph N

Sunday

A slight chance of showers and thunderstorms after noon. Sunny. High near 100, with temperatures falling to around 96 in the afternoon. North wind around 6 mph, with gusts as high as 21 mph. Chance of precipitation is 20%.

Local 7-day forecast

Local Weather Overview

This forecast page for Keystone, SD is designed for quick trip planning, giving you a clean read on daytime highs, overnight lows, and changing conditions across the upcoming forecast window. Latest sync: Jul 26, 2026 12:36 AM MDT.

The active forecast window currently covers Jul 26 to Aug 1, 2026 for Keystone, SD.

Page Snapshot

Page focus: city weather
Forecast window: Jul 26 to Aug 1, 2026
Latest sync: Jul 26, 2026 12:36 AM MDT
Forecast office: UNR
Source: NOAA / NWS

Next High

100°F

Sunday

Next Low

74°F

Sunday Night

Rain Outlook

Periods mentioning precipitation

Windiest

1 to 7 mph

Monday

Daily Outlook

Today

Jul 26

Sunny then Slight Chance Showers And Thunderstorms

100 °F

/ 74°F

Wind 6 mph

Mon

Jul 27

Partly Sunny then Chance Showers And Thunderstorms

94 °F

/ 70°F

Wind 1 to 7 mph

Tue

Jul 28

Mostly Sunny then Chance Showers And Thunderstorms

91 °F

/ 69°F

Wind 6 mph

Wed

Jul 29

Mostly Sunny then Chance Showers And Thunderstorms

92 °F

/ 69°F

Wind 2 to 6 mph

Thu

Jul 30

Mostly Sunny then Chance Showers And Thunderstorms

90 °F

/ 67°F

Wind 6 mph

Fri

Jul 31

Sunny then Chance Showers And Thunderstorms

90 °F

/ 67°F

Wind 6 mph

Sat

Aug 1

Sunny

90 °F

Wind 3 to 7 mph

This Week in Keystone

Sunday looks like the warmest upcoming period in Keystone at 100 degrees F.

Thursday Night is the coolest period ahead with temperatures near 67 degrees F.

The strongest winds are forecast for Monday at about 1 to 7 mph SE.

Precipitation is mentioned in 12 upcoming forecast periods.

Forecast Details

Last updated: Jul 26, 2026 12:36 AM MDT
Coverage: 7 days
Time zone: America/Denver
Forecast office: UNR
Radar station: KUDX

Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.

Open NOAA source

Extended Forecast

Sunday Night

Jul 26

74°F

Slight Chance Showers And Thunderstorms then Mostly Cloudy

1 to 5 mph NW

A slight chance of showers and thunderstorms before midnight. Mostly cloudy, with a low around 74. Northwest wind 1 to 5 mph, with gusts as high as 17 mph. Chance of precipitation is 20%.

Monday

Jul 27

94°F

Partly Sunny then Chance Showers And Thunderstorms

1 to 7 mph SE

A chance of showers and thunderstorms after noon. Partly sunny. High near 94, with temperatures falling to around 84 in the afternoon. Southeast wind 1 to 7 mph, with gusts as high as 22 mph. Chance of precipitation is 50%.

Monday Night

Jul 27

70°F

Chance Showers And Thunderstorms then Mostly Cloudy

6 mph W

A chance of showers and thunderstorms before 9pm, then a chance of showers and thunderstorms between 9pm and midnight. Mostly cloudy, with a low around 70. West wind around 6 mph, with gusts as high as 21 mph. Chance of precipitation is 40%.

Tuesday

Jul 28

91°F

Mostly Sunny then Chance Showers And Thunderstorms

6 mph NE

A chance of showers and thunderstorms after noon. Mostly sunny. High near 91, with temperatures falling to around 88 in the afternoon. Northeast wind around 6 mph, with gusts as high as 20 mph. Chance of precipitation is 30%.

Tuesday Night

Jul 28

69°F

Slight Chance Showers And Thunderstorms then Partly Cloudy

2 to 6 mph S

A slight chance of showers and thunderstorms before midnight. Partly cloudy, with a low around 69.

Wednesday

Jul 29

92°F

Mostly Sunny then Chance Showers And Thunderstorms

2 to 6 mph S

A chance of showers and thunderstorms after noon. Mostly sunny, with a high near 92.

Wednesday Night

Jul 29

69°F

Chance Showers And Thunderstorms then Partly Cloudy

5 mph W

A chance of showers and thunderstorms before midnight. Partly cloudy, with a low around 69.

Thursday

Jul 30

90°F

Mostly Sunny then Chance Showers And Thunderstorms

6 mph N

A chance of showers and thunderstorms after noon. Mostly sunny, with a high near 90.

Thursday Night

Jul 30

67°F

Slight Chance Showers And Thunderstorms then Mostly Clear

5 mph NW

A slight chance of showers and thunderstorms before midnight. Mostly clear, with a low around 67.

Friday

Jul 31

90°F

Sunny then Chance Showers And Thunderstorms

6 mph S

A chance of showers and thunderstorms after noon. Sunny, with a high near 90.

Friday Night

Jul 31

67°F

Slight Chance Showers And Thunderstorms then Mostly Clear

2 to 6 mph S

A slight chance of showers and thunderstorms before midnight. Mostly clear, with a low around 67.

Saturday

Aug 1

90°F

Sunny

3 to 7 mph S

Sunny, with a high near 90.

Detailed Forecast

Period	Conditions	Temp	Wind	Details
Sunday Jul 26	Sunny then Slight Chance Showers And Thunderstorms	100°F	6 mph N	A slight chance of showers and thunderstorms after noon. Sunny. High near 100, with temperatures falling to around 96 in...
Sunday Night Jul 26	Slight Chance Showers And Thunderstorms then Mostly Cloudy	74°F	1 to 5 mph NW	A slight chance of showers and thunderstorms before midnight. Mostly cloudy, with a low around 74. Northwest wind 1 to 5...
Monday Jul 27	Partly Sunny then Chance Showers And Thunderstorms	94°F	1 to 7 mph SE	A chance of showers and thunderstorms after noon. Partly sunny. High near 94, with temperatures falling to around 84 in...
Monday Night Jul 27	Chance Showers And Thunderstorms then Mostly Cloudy	70°F	6 mph W	A chance of showers and thunderstorms before 9pm, then a chance of showers and thunderstorms between 9pm and midnight. M...
Tuesday Jul 28	Mostly Sunny then Chance Showers And Thunderstorms	91°F	6 mph NE	A chance of showers and thunderstorms after noon. Mostly sunny. High near 91, with temperatures falling to around 88 in...
Tuesday Night Jul 28	Slight Chance Showers And Thunderstorms then Partly Cloudy	69°F	2 to 6 mph S	A slight chance of showers and thunderstorms before midnight. Partly cloudy, with a low around 69.
Wednesday Jul 29	Mostly Sunny then Chance Showers And Thunderstorms	92°F	2 to 6 mph S	A chance of showers and thunderstorms after noon. Mostly sunny, with a high near 92.
Wednesday Night Jul 29	Chance Showers And Thunderstorms then Partly Cloudy	69°F	5 mph W	A chance of showers and thunderstorms before midnight. Partly cloudy, with a low around 69.
Thursday Jul 30	Mostly Sunny then Chance Showers And Thunderstorms	90°F	6 mph N	A chance of showers and thunderstorms after noon. Mostly sunny, with a high near 90.
Thursday Night Jul 30	Slight Chance Showers And Thunderstorms then Mostly Clear	67°F	5 mph NW	A slight chance of showers and thunderstorms before midnight. Mostly clear, with a low around 67.
Friday Jul 31	Sunny then Chance Showers And Thunderstorms	90°F	6 mph S	A chance of showers and thunderstorms after noon. Sunny, with a high near 90.
Friday Night Jul 31	Slight Chance Showers And Thunderstorms then Mostly Clear	67°F	2 to 6 mph S	A slight chance of showers and thunderstorms before midnight. Mostly clear, with a low around 67.
Saturday Aug 1	Sunny	90°F	3 to 7 mph S	Sunny, with a high near 90.

Nearby Forecasts

Explore weather pages for nearby cities and major places around Keystone.

Region Links

Pennington County weather

County forecast page

South Dakota weather

Statewide weather overview

United States weather

National weather entry point

Keystone South Dakota business district 3-3-2012 image

Weather data provided by the National Weather Service (NOAA). Forecast pages update automatically as new periods are synced for each supported U.S. location.