Rapid City, SD

South Dakota · Records since 1942–2026

☀️ 78°F Feels like 70°
Currently in Rapid City
As of 12:00 PM MDT

Records for September 11

🔥 Record High

100°F

September 11, 2025

+22° from 78° normal

❄ Record Low

29°F

September 11, 1989

-19° from 48° normal
🌞 Normal high: 78°F 🌑 Normal low: 48°F 1991–2020 normals

All-Time Records — Rapid City

🔥
112°F
Hottest Day Ever
Jul 25, 2026
❄
-31°F
Coldest Day Ever
Feb 2, 1996
🌧
3.78"
Wettest Day Ever
Jun 15, 1963
☃
20.0"
Most Snow in One Day
Apr 9, 2013

First & Last Dates — Rapid City

How early and how late each seasonal turning point has ever arrived, across the full period of record

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Range ever recorded Normal date (1991–2020)
186 days
Longest growing season
1977
110 days
Shortest growing season
1949
135 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 11

# Temp Date
🏆 100°F September 11, 2025
2 97°F September 11, 2024
3 94°F September 11, 1990
4 94°F September 11, 1948
5 93°F September 11, 1993
6 93°F September 11, 1967
7 93°F September 11, 1962
8 93°F September 11, 1959
9 92°F September 11, 2011
10 92°F September 11, 1976

Top 5 Record Lows — September 11

# Temp Date
🥶 29°F September 11, 1989
2 33°F September 11, 2014
3 37°F September 11, 2022
4 37°F September 11, 1955
5 37°F September 11, 1949
About this data — Records are sourced from the NOAA Threadex dataset via RCC ACIS, a quality-controlled record for long-term climate stations. Threadex adjusts for station relocations and observation-time changes, making records comparable across all years since 1942–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Rapid City

threshold: 96°F (90th percentile of historical Jun–Aug highs)
3.7
Avg heat wave length
days (historical)
103°
Avg peak temp
during heat waves
7
Dangerous nights 2026
Overnights ≥ 70°F
2
Heat waves 2026
so far

Days ≥ 90°F Per Year

1942–2026
54
2026 so far
32
Avg/year 1970–2025
35
Avg/year (last 10 complete)
59
Most in a year (1988)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Rapid City

# Dates Days Peak Avg High Avg Overnight Low
🏆 Jul 25, 1987 – Aug 2, 1987 9 105°F (Jul 25) 102°F 68°F
2 Jul 18, 2012 – Jul 24, 2012 7 107°F (Jul 19) 100°F 65°F
3 Jul 10, 2026 – Jul 16, 2026 7 105°F (Jul 12) 101°F 66°F
4 Jul 26, 1988 – Aug 1, 1988 7 104°F (Jul 30) 101°F 64°F
5 Aug 2, 2001 – Aug 8, 2001 7 104°F (Aug 7) 100°F 66°F
6 Aug 22, 1991 – Aug 28, 1991 7 103°F (Aug 25) 100°F 63°F
7 Jul 24, 2026 – Jul 29, 2026 6 112°F (Jul 25) 103°F 66°F
8 Jul 8, 1954 – Jul 13, 1954 6 109°F (Jul 12) 102°F 68°F
9 Jul 18, 1964 – Jul 23, 1964 6 104°F (Jul 21) 100°F 66°F
10 Jul 29, 1955 – Aug 3, 1955 6 102°F (Aug 1) 99°F 68°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

Nights where the overnight low exceeded the 1991–2020 normal low

59
2026 total
above-normal nights
44.8
Avg / summer
1970–2020
74
Most in a summer
2007

Above-Normal Summer Nights Per Year

Average June–August Low by Decade

Overnight lows · complete decades only

Precipitation

Annual totals and trend across the full period of record · see this year's standing →

Monthly Precipitation — Last 24 Months

Blue = actual · dashed line = monthly normal

Annual Precipitation Per Year (1942–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1942, annual totals have trended +0.19" per decade, about +1.6" across the record.

Heavy Rain Days Per Year (≥ 1.0")

Compare year-to-year changes in days with heavy rainfall (≥ 1.0")

This Year — 2026

How Rapid City is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

172 of 253 days with data were above the 1991–2020 normal high for their date.

Precipitation, Year to Date

9.81"
2026 YTD
Normal: 14.39"
-4.58"
0.19"
September so far
September normal: 1.22"
-1.03"
3
2026 heavy rain days
Days with ≥ 1.0"

Accumulation vs. Normal

Running total since Jan 1 against the normal pace for the same date · Rapid City is 4.58" behind the normal pace

Period Review — Aug 11 – Sep 10, 2026

Any window, evaluated against every other year on record — 31 days

Quick picks: Last 7 days Last 30 days Last 90 days This month
Seasons: Spring (Mar–May) Summer (Jun–Aug) Fall (Sep–Nov)
72.9°F
Average temperature
10th-warmest of 85
+3.6°
vs. average
Normal: 69.3°F (1991–2020)
2.36"
Precipitation
12th-wettest of 85
+0.98"
vs. average
Normal: 1.38" · 171% of normal

Average Temperature by Year — Aug 11 – Sep 10

1942–2026 · 2026 highlighted · trend +0.10° per decade (warming since 1942)

Precipitation by Year — Aug 11 – Sep 10

1942–2026 · 2026 highlighted · trend +0.07" per decade (wetter since 1942)

Warmest Aug 11 – Sep 10 on Record

# Year Avg Temp
1 1983 75.0°F
2 1991 74.5°F
3 2003 74.1°F
4 1990 74.1°F
5 2013 74.0°F
6 1998 73.9°F
7 1955 73.5°F
8 2024 73.5°F
9 1978 73.0°F
10 2026 72.9°F

Coolest Aug 11 – Sep 10 on Record

# Year Avg Temp
1 1968 62.8°F
2 1992 63.0°F
3 1946 64.0°F
4 1964 64.1°F
5 1987 64.9°F
6 2008 65.2°F
7 1974 65.2°F
8 1962 65.3°F
9 1951 65.3°F
10 1966 65.5°F

Wettest Aug 11 – Sep 10 on Record

# Year Total
1 1951 3.84"
2 2015 3.34"
3 1986 3.32"
4 1989 3.29"
5 1990 3.02"
6 1966 3.01"
7 1997 2.74"
8 1946 2.58"
9 2007 2.44"
10 1983 2.43"

Driest Aug 11 – Sep 10 on Record

# Year Total
1 1988 0.06"
2 1959 0.07"
3 1942 0.09"
4 1944 0.18"
5 2000 0.21"
6 2009 0.27"
7 1958 0.29"
8 1975 0.30"
9 1969 0.31"
10 1947 0.35"
About this data. Pick any start and end date and this becomes the same kind of review as the Month and Fall tabs, just for exactly the window you asked for — the generalized version of the same engine, evaluated across every year on record. Average temperature is the mean of each day's (high + low) / 2; precipitation is the sum of daily totals. A year missing more than about a fifth of the window's days is excluded from the temperature ranking; any missing day excludes a year from the precipitation ranking, since an unreported day is unreported rain. Ranges that cross from December into January aren't supported yet. Normals are the 1991–2020 mean for the same window.
← Back to all stations