As of 04:38 MDT

Weather in Keystone, SD

49°

Keystone, Thursday, 8 October, 04:38

Clear. Feels like 49°. High 74°, low 46°.

Pressure30.06 inHg

Wind1.7 mph W

Humidity63%

Visibility6.2 mi

Dew point37°

See detailed hourly forecast

Monthly outlook for Keystone, SD: average high 62.6°, average low 41.6°. That is 1.2° above the climate normal for October. Precipitation is expected on 3 days (about 0.3 inches), against a normal of 3 days and 0.9 inches. The warmest day looks like 9 October (82.3°), the coolest 17 October (27.9°).

62.6°/41.6°

Average high / low

+1.2°

Above normal

3 / 3

Wet days / normal

0.3 in

Precipitation this month

Ten-day blocks vs climate normal

Period	Forecast high	Normal	Difference
8 October – 17 October	62.6°	61°	+0.9°
18 October – 27 October	62.5°	58.5°	+2.2°
28 October – 6 November	at normal	52.5°	—

October records over 66 years

90.3°3 October 2025All-time high

-4.2°26 October 2020All-time low

Climate normals and records are computed from the nearest reference point — Hermosa (12 mi).

Fri, 0982° / 41°

82 °

Keystone, Friday, 9 October

Clear. High 82°, low 41°.

Pressure29.68 inHg

Wind10.8 mph SW

Humidity18%

Visibility6.2 mi

Dew point32°

Sat, 1081° / 59°

81 °

Keystone, Saturday, 10 October

Light rain. High 81°, low 59°.

Pressure29.53 inHg

Wind10.8 mph SW

Humidity17%

Visibility6.2 mi

Dew point31°

Sun, 1161° / 46°

61 °

Keystone, Sunday, 11 October

Overcast. High 61°, low 46°.

Pressure29.77 inHg

Wind5.6 mph NE

Humidity59%

Visibility6.2 mi

Dew point46°

Mon, 1249° / 38°

0.02

49 °

Keystone, Monday, 12 October

Light rain. High 49°, low 38°.

Pressure29.91 inHg

Wind7.2 mph NE

Humidity86%

Visibility—

Dew point42°

Tue, 1353° / 36°

0.1

53 °

Keystone, Tuesday, 13 October

Light rain. High 53°, low 36°.

Pressure30.06 inHg

Wind9.2 mph SE

Humidity64%

Visibility—

Dew point35°

Wed, 1472° / 51°

0.09

72 °

Keystone, Wednesday, 14 October

Light rain. High 72°, low 51°.

Pressure29.35 inHg

Wind19.1 mph W

Humidity55%

Visibility—

Dew point47°

Thu, 1555° / 35°

55 °

Keystone, Thursday, 15 October

Partly cloudy. High 55°, low 35°.

Pressure29.62 inHg

Wind26.4 mph W

Humidity48%

Visibility—

Dew point27°

Fri, 1644° / 32°

0.07

44 °

Keystone, Friday, 16 October

Light snow. High 44°, low 32°.

Pressure30.33 inHg

Wind18.9 mph NW

Humidity43%

Visibility—

Dew point22°

Sat, 1756° / 28°

56 °

Keystone, Saturday, 17 October

Clear. High 56°, low 28°.

Pressure30.09 inHg

Wind10.4 mph SW

Humidity40%

Visibility—

Dew point25°

Sun, 1856° / 37°

56 °

Keystone, Sunday, 18 October

Clear. High 56°, low 37°.

Pressure30.15 inHg

Wind7.9 mph E

Humidity29%

Visibility—

Dew point21°

Mon, 1964° / 39°

64 °

Keystone, Monday, 19 October

Clear. High 64°, low 39°.

Pressure30.00 inHg

Wind7.3 mph NE

Humidity20%

Visibility—

Dew point20°

Tue, 2066° / 44°

66 °

Keystone, Tuesday, 20 October

Overcast. High 66°, low 44°.

Pressure30.06 inHg

Wind10.7 mph S

Humidity24%

Visibility—

Dew point24°

Wed, 2171° / 48°

71 °

Keystone, Wednesday, 21 October

Partly cloudy. High 71°, low 48°.

Pressure29.50 inHg

Wind22.7 mph SW

Humidity16%

Visibility—

Dew point18°

Thu, 2257° / 40°

57 °

Keystone, Thursday, 22 October

Partly cloudy. High 57°, low 40°.

Pressure29.50 inHg

Wind14.7 mph W

Humidity26%

Visibility—

Dew point18°

Fri, 2361° / 46°

61 °

Keystone, Friday, 23 October

Mostly clear. High 61°, low 46°.

Pressure29.56 inHg

Wind25.2 mph W

Humidity33%

Visibility—

Dew point31°

From day 17 onward the outlook is built from 60-year climate statistics

Sat, 2457° / 37°

0.04

57 °

Keystone, Saturday, 24 October

Climate normal for this date — 60-year average.

Average high57°

Average low37°

Average precipitation0.04 in

Chance of precipitation15%

Record high77° (1960)

Record low10° (2002)

Sun, 2558° / 37°

0.02

58 °

Keystone, Sunday, 25 October

Climate normal for this date — 60-year average.

Average high58°

Average low37°

Average precipitation0.02 in

Chance of precipitation10%

Record high78° (2017)

Record low10° (2020)

Mon, 2658° / 37°

0.05

58 °

Keystone, Monday, 26 October

Climate normal for this date — 60-year average.

Average high58°

Average low37°

Average precipitation0.05 in

Chance of precipitation10%

Record high76° (1990)

Record low-4° (2020)

Tue, 2756° / 35°

0.03

56 °

Keystone, Tuesday, 27 October

Climate normal for this date — 60-year average.

Average high56°

Average low35°

Average precipitation0.03 in

Chance of precipitation23%

Record high78° (2016)

Record low8° (2020)

Wed, 2856° / 35°

0.07

56 °

Keystone, Wednesday, 28 October

Climate normal for this date — 60-year average.

Average high56°

Average low35°

Average precipitation0.07 in

Chance of precipitation22%

Record high78° (2016)

Record low13° (1991)

Thu, 2954° / 35°

0.07

54 °

Keystone, Thursday, 29 October

Climate normal for this date — 60-year average.

Average high54°

Average low35°

Average precipitation0.07 in

Chance of precipitation35%

Record high78° (1968)

Record low8° (1991)

Fri, 3052° / 34°

0.04

52 °

Keystone, Friday, 30 October

Climate normal for this date — 60-year average.

Average high52°

Average low34°

Average precipitation0.04 in

Chance of precipitation22%

Record high77° (1968)

Record low3° (1991)

Sat, 3152° / 34°

0.03

52 °

Keystone, Saturday, 31 October

Climate normal for this date — 60-year average.

Average high52°

Average low34°

Average precipitation0.03 in

Chance of precipitation15%

Record high74° (1990)

Record low3° (1991)

Sun, 0151° / 33°

0.05

51 °

Keystone, Sunday, 1 November

Climate normal for this date — 60-year average.

Average high51°

Average low33°

Average precipitation0.05 in

Chance of precipitation18%

Record high72° (1965)

Record low3° (2002)

Mon, 0251° / 32°

0.04

51 °

Keystone, Monday, 2 November

Climate normal for this date — 60-year average.

Average high51°

Average low32°

Average precipitation0.04 in

Chance of precipitation20%

Record high75° (2008)

Record low-2° (1991)

Tue, 0351° / 33°

0.04

51 °

Keystone, Tuesday, 3 November

Climate normal for this date — 60-year average.

Average high51°

Average low33°

Average precipitation0.04 in

Chance of precipitation20%

Record high71° (2020)

Record low2° (1991)

Wed, 0453° / 32°

0.01

53 °

Keystone, Wednesday, 4 November

Climate normal for this date — 60-year average.

Average high53°

Average low32°

Average precipitation0.01 in

Chance of precipitation10%

Record high76° (1978)

Record low7° (1995)

Thu, 0552° / 33°

0.03

52 °

Keystone, Thursday, 5 November

Climate normal for this date — 60-year average.

Average high52°

Average low33°

Average precipitation0.03 in

Chance of precipitation13%

Record high76° (2020)

Record low1° (2003)

Fri, 0651° / 32°

0.04

51 °

Keystone, Friday, 6 November

Climate normal for this date — 60-year average.

Average high51°

Average low32°

Average precipitation0.04 in

Chance of precipitation13%

Record high75° (2020)

Record low-3° (2003)

About the monthly outlook

How accurate is a 30-day forecast?

The first 16 days come from weather models — reliable for the first 3–5 days and progressively less so after that. Days 17 through 30 for Keystone, SD are built from the climate normal, the 60-year average, so they show typical weather for those dates rather than a specific forecast.

What does "above normal" mean?

We compare the forecast against the climate normal for those exact calendar days, computed from 60 years of observations. The deviation shows how much the coming month differs from a typical one.

Where do the 66-year records come from?

They are real temperature extremes recorded in Keystone, SD since 1960: the highest and lowest reading for each calendar date, with the year it happened.

How often is it updated?

The forecast portion refreshes every hour; the climate portion is based on long-term data and stays stable.