Rapid City Downtown, SD

South Dakota · Records since 1888–2026

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

Records for September 11

🔥 Record High

95°F

September 11, 2025

+19° from 76° normal

❄ Record Low

29°F

September 11, 1921

-24° from 53° normal
🌞 Normal high: 76°F 🌑 Normal low: 53°F 1991–2020 normals

All-Time Records — Rapid City Downtown

🔥
110°F
Hottest Day Ever
Jul 25, 2026
❄
-34°F
Coldest Day Ever
Feb 11, 1899
🌧
5.57"
Wettest Day Ever
May 27, 1926
☃
20.0"
Most Snow in One Day
Apr 18, 1970

First & Last Dates — Rapid City Downtown

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)
196 days
Longest growing season
1940
111 days
Shortest growing season
1949
154 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 11

# Temp Date
🏆 95°F September 11, 2025
2 95°F September 11, 2024
3 94°F September 11, 1908
4 93°F September 11, 1971
5 93°F September 11, 1948
6 93°F September 11, 1939
7 92°F September 11, 1962
8 92°F September 11, 1959
9 92°F September 11, 1893
10 91°F September 11, 2011

Top 5 Record Lows — September 11

# Temp Date
🥶 29°F September 11, 1921
2 32°F September 11, 2014
3 36°F September 11, 1964
4 36°F September 11, 1955
5 36°F September 11, 1903
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 1888–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Rapid City Downtown

threshold: 94°F (90th percentile of historical Jun–Aug highs)
3.8
Avg heat wave length
days (historical)
101°
Avg peak temp
during heat waves
13
Dangerous nights 2026
Overnights ≥ 70°F
3
Heat waves 2026
so far

Days ≥ 90°F Per Year

1888–2026
49
2026 so far
25
Avg/year 1970–2025
29
Avg/year (last 10 complete)
55
Most in a year (1936)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Rapid City Downtown

# Dates Days Peak Avg High Avg Overnight Low
🏆 Jul 2, 1936 – Jul 11, 1936 10 106°F (Jul 5) 102°F 71°F
2 Jul 21, 1931 – Jul 27, 1931 7 105°F (Jul 25) 100°F 70°F
3 Jul 10, 2026 – Jul 16, 2026 7 105°F (Jul 12) 101°F 68°F
4 Jul 18, 2012 – Jul 24, 2012 7 103°F (Jul 19) 98°F 68°F
5 Sep 4, 1931 – Sep 10, 1931 7 101°F (Sep 7) 98°F 64°F
6 Jul 24, 2026 – Jul 29, 2026 6 110°F (Jul 25) 102°F 70°F
7 Jul 8, 1954 – Jul 13, 1954 6 107°F (Jul 9) 101°F 70°F
8 Jul 21, 1936 – Jul 26, 1936 6 106°F (Jul 23) 99°F 68°F
9 Jul 17, 1934 – Jul 22, 1934 6 104°F (Jul 18) 100°F 70°F
10 Jul 14, 1936 – Jul 19, 1936 6 104°F (Jul 19) 100°F 70°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
44.7
Avg / summer
1970–2020
63
Most in a summer
1936

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 (1888–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1888, annual totals have trended +0.18" per decade, about +2.5" 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 Downtown is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

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

Precipitation, Year to Date

11.17"
2026 YTD
Normal: 16.73"
-5.56"
0.03"
September so far
September normal: 1.40"
-1.37"
2
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 Downtown is 5.56" 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)
74.8°F
Average temperature
3rd-warmest of 115
+4.7°
vs. average
Normal: 70.0°F (1991–2020)
4.19"
Precipitation
2nd-wettest of 114
+2.43"
vs. average
Normal: 1.76" · 238% of normal

Average Temperature by Year — Aug 11 – Sep 10

1888–2026 · 2026 highlighted · trend +0.26° per decade (warming since 1888)

Precipitation by Year — Aug 11 – Sep 10

1888–2026 · 2026 highlighted · trend +0.05" per decade (wetter since 1888)

Warmest Aug 11 – Sep 10 on Record

# Year Avg Temp
1 2013 75.6°F
2 1970 74.8°F
3 2026 74.8°F
4 2022 74.8°F
5 2003 74.7°F
6 1998 74.4°F
7 1937 74.3°F
8 1931 73.9°F
9 1955 73.7°F
10 1936 73.7°F

Coolest Aug 11 – Sep 10 on Record

# Year Avg Temp
1 1920 64.5°F
2 1910 64.5°F
3 1946 64.5°F
4 1968 64.8°F
5 1911 65.0°F
6 1918 65.0°F
7 1964 65.0°F
8 1915 65.1°F
9 1914 65.3°F
10 1890 65.4°F

Wettest Aug 11 – Sep 10 on Record

# Year Total
1 1951 5.50"
2 2026 4.19"
3 1915 3.63"
4 1932 3.54"
5 2007 3.50"
6 1949 3.26"
7 1946 3.19"
8 1963 2.92"
9 1997 2.88"
10 1903 2.82"

Driest Aug 11 – Sep 10 on Record

# Year Total
1 1897 0.01"
2 1889 0.02"
3 1942 0.09"
4 1969 0.11"
5 1910 0.12"
6 1899 0.15"
7 1928 0.16"
8 1917 0.17"
9 1894 0.20"
10 1959 0.22"
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.
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