Des Moines, IA

Iowa · Records since 1878–2026

⛅ 75°F Feels like 80°
Currently in Des Moines
As of 1:45 PM CDT

Records for September 7

🔥 Record High

101°F

September 7, 1939

+21° from 80° normal

❄ Record Low

41°F

September 7, 1986

-18° from 59° normal
🌞 Normal high: 80°F 🌑 Normal low: 59°F 1991–2020 normals

All-Time Records — Des Moines

🔥
110°F
Hottest Day Ever
Jul 25, 1936
❄
-30°F
Coldest Day Ever
Jan 5, 1884
🌧
6.18"
Wettest Day Ever
Aug 27, 1975
☃
19.8"
Most Snow in One Day
Jan 1, 1942

Top 10 Record Highs — September 7

# Temp Date
🏆 101°F September 7, 1939
2 98°F September 7, 1931
3 97°F September 7, 1978
4 96°F September 7, 2013
5 96°F September 7, 1922
6 95°F September 7, 1985
7 94°F September 7, 1959
8 94°F September 7, 1938
9 94°F September 7, 1897
10 94°F September 7, 1893

Top 5 Record Lows — September 7

# Temp Date
🥶 41°F September 7, 1986
2 42°F September 7, 1956
3 43°F September 7, 2025
4 43°F September 7, 1953
5 45°F September 7, 1944
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 1878–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Des Moines

threshold: 93°F (90th percentile of historical Jun–Aug highs)
4.5
Avg heat wave length
days (historical)
99°
Avg peak temp
during heat waves
35
Dangerous nights 2026
Overnights ≥ 70°F
1
Heat waves 2026
so far

2026 Daily High Temperature vs Normal

Year to date
Above normal Below normal

148 of 249 days with data were above the 1991–2020 normal high for their date.

Days ≥ 90°F Per Year

1878–2026
26
2026 so far
25
Avg/year 1970–2025
29
Avg/year (last 10 complete)
68
Most in a year (1934)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Des Moines

# Dates Days Peak Avg High Avg Overnight Low
🏆 Jul 9, 1901 – Jul 27, 1901 19 109°F (Jul 22) 100°F 74°F
2 Jul 3, 1936 – Jul 19, 1936 17 109°F (Jul 4) 103°F 76°F
3 Aug 2, 1947 – Aug 13, 1947 12 102°F (Aug 3) 98°F 73°F
4 Jul 25, 1955 – Aug 4, 1955 11 105°F (Jul 31) 98°F 76°F
5 Jul 12, 1932 – Jul 22, 1932 11 98°F (Jul 19) 96°F 72°F
6 Jul 24, 1987 – Aug 2, 1987 10 101°F (Aug 1) 98°F 74°F
7 Jul 1, 1886 – Jul 9, 1886 9 104°F (Jul 5) 99°F 71°F
8 Jul 22, 1916 – Jul 30, 1916 9 100°F (Jul 27) 98°F 73°F
9 Jun 23, 1931 – Jul 1, 1931 9 99°F (Jun 28) 97°F 76°F
10 Aug 25, 1953 – Sep 2, 1953 9 97°F (Aug 30) 95°F 69°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

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

57
2026 total
above-normal nights
46.6
Avg / summer
1970–2020
72
Most in a summer
2010

Above-Normal Summer Nights Per Year

Average June–August Low by Decade

Overnight lows · complete decades only

Precipitation

Actual vs. 1991–2020 full-month and full-season normals

33.45"
2026 YTD
Normal: 27.79"
+5.66"
1.37"
September so far
September normal: 3.18"
-1.81"
12
2026 heavy rain days
Days with ≥ 1.0"

2026 Accumulation vs. Normal

Running total since Jan 1 against the normal pace for the same date · Des Moines is 5.66" ahead of the normal pace

Monthly Precipitation — Last 24 Months

Blue = actual · dashed line = monthly normal

Annual Precipitation Per Year (1878–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1878, annual totals have trended +0.36" per decade, about +5.2" across the record.

Heavy Rain Days Per Year (≥ 1.0")

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

Month in Review — August 2026

75.2°F

Average temperature · August 2026

157th-warmest month on record

44th-warmest August of 149 on record

+0.9° vs. 74.3° average (1991–2020)
85.8°F
Warmest month ever
July 1936
83.3°F
Warmest August ever
1983
98°F
Hottest of 2026
Jul 20

Average August Temperature by Year

1878–2026 · 2026 highlighted · trend +0.10° per decade (warming since 1878)

Precipitation — August 2026

Month total against the 1991–2020 average and every other August on record

5.83"
Total precipitation
August 2026
+1.66"
vs. average
Normal: 4.17" · 140% of normal
26th-wettest
August rank
of 148 on record
13.68"
Wettest August ever
1977 · driest 0.14" (1909)

August Precipitation by Year

1878–2026 · 2026 highlighted · trend +0.06" per decade (wetter since 1878)

Wettest Augusts on Record

# Year Total
1 1977 13.68"
2 1993 12.24"
3 2014 11.36"
4 2010 10.75"
5 1954 10.47"
6 1987 10.04"
7 1975 9.73"
8 1940 9.63"
9 1932 8.40"
10 1900 8.02"

Driest Augusts on Record

# Year Total
1 1909 0.14"
2 1984 0.25"
3 2003 0.67"
4 1901 0.67"
5 1953 0.71"
6 1967 0.79"
7 1947 0.93"
8 2013 0.98"
9 1930 1.00"
10 1995 1.04"

Warmest Augusts on Record

# Year Avg Temp
1 1983 83.3°F
2 1947 82.2°F
3 1936 80.4°F
4 1881 79.3°F
5 1995 79.1°F
6 1988 78.8°F
7 1937 78.7°F
8 1913 78.7°F
9 1918 78.7°F
10 1886 78.5°F

Warmest Months on Record (Any Month)

# Month Avg Temp
1 July 1936 85.8°F
2 July 2012 84.3°F
3 July 1901 83.9°F
4 August 1983 83.3°F
5 July 1934 82.6°F
6 August 1947 82.2°F
7 July 2011 81.7°F
8 July 1916 81.5°F
9 July 1955 81.0°F
10 July 1977 81.0°F

Nearby Stations — August 2026

How the same month ranked at the closest reporting stations

Station Avg Temp August Rank
Des Moines, IA 75.2°F 44th of 149
Waterloo, IA 71.7°F 53rd of 132
Cedar Rapids, IA 72.3°F 56th of 134
Omaha, NE 76.5°F 44th of 156
Spencer, IA 70.0°F 69th of 112
About this data. Monthly averages are the mean of daily average temperatures, computed from NOAA Threadex records via RCC ACIS. Months missing more than three days of observations are excluded from the rankings, so the in-progress month never appears. Rankings cover 1,777 complete months on record. Precipitation totals sum the daily reports for the month, with trace amounts counted as zero. A month missing any day of precipitation data is left out entirely (an unreported day is unreported rain), so the precipitation ranking covers 148 complete Augusts. Normals are the 1991–2020 mean for the same calendar month. Trend lines are a least-squares fit across every year shown.

Fall in Review — Fall 2026

September 1 – November 30, 2026

Fall 2026 is still under way. Season totals and rankings appear once November closes; the markers below update as they happen.

Summer to Winter — 2026

Each turning point of the season against its 1991–2020 normal date, with the earliest and latest on record

Marker 2026 Normal vs. normal Earliest Latest Drift
Last 90°F day
The final day of summer heat
 Sep 5
so far
 Sep 7 Jun 25, 1950 Oct 12, 1975 +0.4 d/decade
Last 80°F day
The last genuinely warm afternoon
 Sep 6
so far
 Oct 12 Sep 9, 1964 Nov 13, 1999 +0.3 d/decade
First high below 50°F
The first afternoon that stays cold
 not yet Oct 21 Sep 16, 1881 Nov 19, 2016 +0.4 d/decade
First 32°F freeze
Growing season over
 not yet Oct 18 Sep 22, 1913 Nov 12, 2016 +0.3 d/decade
First 28°F hard freeze
Cold enough to end tender growth
 not yet Oct 29 Sep 28, 1942 Nov 26, 2009 +0.3 d/decade
First 20°F night
Winter cold arriving
 not yet Nov 18 Oct 13, 1909 Dec 23, 2001 +0.4 d/decade
First measurable snow
0.1" or more in a day
 not yet Nov 15 Oct 10, 2009 Dec 26, 1939 -0.1 d/decade

Drift is a least-squares fit across every year on record. Positive means the marker has been arriving later.

First Freeze by Year

The first 32°F night of each autumn since 1878 · trending +0.3 days later per decade

182
Normal length
1991–2020 average
222
Longest on record
2015
147
Shortest on record
1885

Growing Season Length by Year

Days between the last spring freeze and the first fall freeze · trending +0.2 days longer per decade

Fall Average Temperature by Year

1878–2025 · 2026 highlighted · trend +0.11° per decade (warming since 1878)

Fall Precipitation by Year

1878–2025 · 2026 highlighted · trend +0.01" per decade (wetter since 1878)

About this data. Fall is meteorological autumn, September 1 through November 30, the window NOAA uses for seasonal statistics. Seasonal temperature is the day-weighted mean of the three monthly means; precipitation is their sum, and a season missing any of the three months is left out of the rankings. Freeze, heat and snow markers come from daily NOAA Threadex observations via RCC ACIS: freezes and snow are the first occurrence on or after July 1, and the last 90°F and 80°F days are the final ones anywhere in the calendar year. Growing season counts the freeze-free days between the last spring 32°F and the first fall 32°F.
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