Des Moines, IA

Iowa · Records since 1878–2026

☀️ 78°F Feels like 83°
Currently in Des Moines
As of 1:30 PM CDT

Records for September 11

🔥 Record High

97°F

September 11, 2000

+18° from 79° normal

❄ Record Low

40°F

September 11, 1955

-17° from 57° normal
🌞 Normal high: 79°F 🌑 Normal low: 57°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

First & Last Dates — Des Moines

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)
222 days
Longest growing season
2015
147 days
Shortest growing season
1885
182 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 11

# Temp Date
🏆 97°F September 11, 2000
2 97°F September 11, 1936
3 96°F September 11, 1927
4 94°F September 11, 2012
5 94°F September 11, 1895
6 92°F September 11, 2005
7 92°F September 11, 1931
8 91°F September 11, 2021
9 91°F September 11, 1978
10 91°F September 11, 1939

Top 5 Record Lows — September 11

# Temp Date
🥶 40°F September 11, 1955
2 41°F September 11, 1917
3 42°F September 11, 1940
4 42°F September 11, 1894
5 43°F September 11, 1959
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

Days ≥ 90°F Per Year

1878–2026
27
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

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 (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")

This Year — 2026

How Des Moines is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

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

Precipitation, Year to Date

39.47"
2026 YTD
Normal: 28.23"
+11.24"
7.39"
September so far
September normal: 3.18"
+4.21"
14
2026 heavy rain days
Days with ≥ 1.0"

Accumulation vs. Normal

Running total since Jan 1 against the normal pace for the same date · Des Moines is 11.24" ahead of the normal pace

Period Review — Sep 1 – Nov 30, 2026

Any window, evaluated against every other year on record — 91 days

Quick picks: Last 7 days Last 30 days Last 90 days This month
Seasons: Spring (Mar–May) Summer (Jun–Aug) Fall (Sep–Nov)
2026 is still under way for this window — totals and rankings appear once November 30 passes.

Average Temperature by Year — Sep 1 – Nov 30

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

Precipitation by Year — Sep 1 – Nov 30

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

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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