As of 07:34 MDT

Weather in Rapid City, SD

68°

Rapid City, Sunday, 9 August, 07:34

Overcast. Feels like 66°. High 92°, low 66°.

Pressure29.91 inHg

Wind8.2 mph N

Humidity42%

Visibility6.2 mi

Dew point44°

See detailed hourly forecast

Monthly outlook for Rapid City, SD: average high 90°, average low 66.3°. That is 3.6° above the climate normal for August. Precipitation is expected on 4 days (about 1.9 inches), against a normal of 3 days and 0.8 inches. The warmest day looks like 24 August (101.1°), the coolest 15 August (61.5°).

90°/66.3°

Average high / low

+3.6°

Above normal

4 / 3

Wet days / normal

1.9 in

Precipitation this month

Ten-day blocks vs climate normal

Period	Forecast high	Normal	Difference
9 August – 18 August	87.1°	83.5°	+2°
19 August – 28 August	94.9°	83.5°	+6.3°
29 August – 7 September	at normal	81.3°	—

August records over 66 years

103.8°29 August 2012All-time high

41.4°23 August 1966All-time low

Climate normals and records are computed from the nearest reference point — Green Valley (6 mi).

Mon, 1099° / 63°

99 °

Rapid City, Monday, 10 August

Partly cloudy. High 99°, low 63°.

Pressure29.77 inHg

Wind14.8 mph SE

Humidity28%

Visibility6.2 mi

Dew point52°

Tue, 1193° / 63°

0.01

93 °

Rapid City, Tuesday, 11 August

Light rain. High 93°, low 63°.

Pressure29.80 inHg

Wind10.6 mph E

Humidity37%

Visibility6.2 mi

Dew point57°

Wed, 1296° / 67°

0.02

96 °

Rapid City, Wednesday, 12 August

Light rain. High 96°, low 67°.

Pressure29.77 inHg

Wind13.1 mph SE

Humidity32%

Visibility6.2 mi

Dew point56°

Thu, 1371° / 64°

0.04

71 °

Rapid City, Thursday, 13 August

Light rain. High 71°, low 64°.

Pressure29.97 inHg

Wind12.1 mph SE

Humidity85%

Visibility—

Dew point61°

Fri, 1468° / 62°

0.24

68 °

Rapid City, Friday, 14 August

Rain. High 68°, low 62°.

Pressure29.97 inHg

Wind15.7 mph SE

Humidity95%

Visibility—

Dew point62°

Sat, 1582° / 61°

0.04

82 °

Rapid City, Saturday, 15 August

Light rain. High 82°, low 61°.

Pressure30.06 inHg

Wind8.7 mph N

Humidity54%

Visibility—

Dew point57°

Sun, 1687° / 64°

1.48

87 °

Rapid City, Sunday, 16 August

Heavy rain. High 87°, low 64°.

Pressure30.09 inHg

Wind16 mph SE

Humidity41%

Visibility—

Dew point56°

Mon, 1791° / 65°

0.02

91 °

Rapid City, Monday, 17 August

Light rain. High 91°, low 65°.

Pressure29.83 inHg

Wind10.4 mph S

Humidity43%

Visibility—

Dew point59°

Tue, 1891° / 72°

91 °

Rapid City, Tuesday, 18 August

Partly cloudy. High 91°, low 72°.

Pressure29.88 inHg

Wind22.5 mph N

Humidity19%

Visibility—

Dew point40°

Wed, 1988° / 65°

88 °

Rapid City, Wednesday, 19 August

Clear. High 88°, low 65°.

Pressure29.97 inHg

Wind11.8 mph E

Humidity35%

Visibility—

Dew point50°

Thu, 20100° / 68°

100 °

Rapid City, Thursday, 20 August

Clear. High 100°, low 68°.

Pressure29.80 inHg

Wind16.4 mph NW

Humidity10%

Visibility—

Dew point28°

Fri, 2197° / 74°

97 °

Rapid City, Friday, 21 August

Partly cloudy. High 97°, low 74°.

Pressure29.77 inHg

Wind20.4 mph N

Humidity12%

Visibility—

Dew point33°

Sat, 2287° / 65°

87 °

Rapid City, Saturday, 22 August

Clear. High 87°, low 65°.

Pressure30.06 inHg

Wind14.4 mph SE

Humidity30%

Visibility—

Dew point46°

Sun, 2396° / 68°

96 °

Rapid City, Sunday, 23 August

Overcast. High 96°, low 68°.

Pressure29.94 inHg

Wind9.1 mph S

Humidity27%

Visibility—

Dew point49°

Mon, 24101° / 74°

101 °

Rapid City, Monday, 24 August

Clear. High 101°, low 74°.

Pressure29.94 inHg

Wind11.1 mph NE

Humidity13%

Visibility—

Dew point36°

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

Tue, 2583° / 61°

0.02

83 °

Rapid City, Tuesday, 25 August

Climate normal for this date — 60-year average.

Average high83°

Average low61°

Average precipitation0.02 in

Chance of precipitation20%

Record high96° (2020)

Record low44° (1964)

Wed, 2683° / 60°

0.08

83 °

Rapid City, Wednesday, 26 August

Climate normal for this date — 60-year average.

Average high83°

Average low60°

Average precipitation0.08 in

Chance of precipitation30%

Record high102° (1970)

Record low49° (1992)

Thu, 2783° / 60°

0.07

83 °

Rapid City, Thursday, 27 August

Climate normal for this date — 60-year average.

Average high83°

Average low60°

Average precipitation0.07 in

Chance of precipitation25%

Record high102° (2010)

Record low46° (1987)

Fri, 2883° / 60°

0.03

83 °

Rapid City, Friday, 28 August

Climate normal for this date — 60-year average.

Average high83°

Average low60°

Average precipitation0.03 in

Chance of precipitation8%

Record high96° (1969)

Record low46° (1987)

Sat, 2983° / 60°

0.04

83 °

Rapid City, Saturday, 29 August

Climate normal for this date — 60-year average.

Average high83°

Average low60°

Average precipitation0.04 in

Chance of precipitation18%

Record high104° (2012)

Record low48° (1988)

Sun, 3083° / 60°

0.03

83 °

Rapid City, Sunday, 30 August

Climate normal for this date — 60-year average.

Average high83°

Average low60°

Average precipitation0.03 in

Chance of precipitation18%

Record high98° (1989)

Record low43° (1992)

Mon, 3181° / 60°

0.02

81 °

Rapid City, Monday, 31 August

Climate normal for this date — 60-year average.

Average high81°

Average low60°

Average precipitation0.02 in

Chance of precipitation10%

Record high99° (1960)

Record low45° (1962)

Tue, 0181° / 59°

0.06

81 °

Rapid City, Tuesday, 1 September

Climate normal for this date — 60-year average.

Average high81°

Average low59°

Average precipitation0.06 in

Chance of precipitation17%

Record high99° (2012)

Record low44° (1965)

Wed, 0282° / 59°

0.07

82 °

Rapid City, Wednesday, 2 September

Climate normal for this date — 60-year average.

Average high82°

Average low59°

Average precipitation0.07 in

Chance of precipitation15%

Record high99° (1960)

Record low42° (1974)

Thu, 0382° / 58°

0.02

82 °

Rapid City, Thursday, 3 September

Climate normal for this date — 60-year average.

Average high82°

Average low58°

Average precipitation0.02 in

Chance of precipitation13%

Record high97° (2007)

Record low40° (1974)

Fri, 0481° / 58°

0.06

81 °

Rapid City, Friday, 4 September

Climate normal for this date — 60-year average.

Average high81°

Average low58°

Average precipitation0.06 in

Chance of precipitation20%

Record high100° (1960)

Record low41° (1968)

Sat, 0581° / 58°

0.04

81 °

Rapid City, Saturday, 5 September

Climate normal for this date — 60-year average.

Average high81°

Average low58°

Average precipitation0.04 in

Chance of precipitation13%

Record high102° (2020)

Record low39° (1968)

Sun, 0680° / 57°

0.02

80 °

Rapid City, Sunday, 6 September

Climate normal for this date — 60-year average.

Average high80°

Average low57°

Average precipitation0.02 in

Chance of precipitation17%

Record high99° (1978)

Record low41° (2025)

Mon, 0779° / 56°

0.04

79 °

Rapid City, Monday, 7 September

Climate normal for this date — 60-year average.

Average high79°

Average low56°

Average precipitation0.04 in

Chance of precipitation15%

Record high97° (2022)

Record low42° (1986)

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 Rapid City, 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 Rapid City, 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.