Dubuque, IA

Iowa · Records since 1874–2026

☀️ 80°F
Currently in Dubuque
As of 1:30 PM CDT

Records for September 11

🔥 Record High

96°F

September 11, 1895

+21° from 75° normal

❄ Record Low

36°F

September 11, 1917

-18° from 54° normal
🌞 Normal high: 75°F 🌑 Normal low: 54°F 1991–2020 normals

All-Time Records — Dubuque

🔥
110°F
Hottest Day Ever
Jul 14, 1936
❄
-32°F
Coldest Day Ever
Jan 7, 1887
🌧
8.85"
Wettest Day Ever
Sep 14, 1967
☃
15.0"
Most Snow in One Day
Mar 5, 1959

First & Last Dates — Dubuque

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)
208 days
Longest growing season
1900
132 days
Shortest growing season
1883
163 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 11

# Temp Date
🏆 96°F September 11, 1895
2 94°F September 11, 1931
3 92°F September 11, 1906
4 90°F September 11, 1978
5 89°F September 11, 2005
6 89°F September 11, 1908
7 88°F September 11, 2000
8 88°F September 11, 1942
9 88°F September 11, 1920
10 88°F September 11, 1874

Top 5 Record Lows — September 11

# Temp Date
🥶 36°F September 11, 1917
2 37°F September 11, 1955
3 40°F September 11, 1992
4 40°F September 11, 1962
5 40°F September 11, 1898
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 1874–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Dubuque

threshold: 90°F (90th percentile of historical Jun–Aug highs)
4.4
Avg heat wave length
days (historical)
96°
Avg peak temp
during heat waves
14
Dangerous nights 2026
Overnights ≥ 70°F
2
Heat waves 2026
so far

Days ≥ 90°F Per Year

1874–2026
13
2026 so far
14
Avg/year 1970–2025
7
Avg/year (last 10 complete)
42
Most in a year (1934)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Dubuque

# Dates Days Peak Avg High Avg Overnight Low
🏆 Jul 12, 1901 – Jul 27, 1901 16 106°F (Jul 21) 98°F 73°F
2 Jul 5, 1936 – Jul 18, 1936 14 110°F (Jul 14) 103°F 73°F
3 Jul 23, 1941 – Aug 4, 1941 13 100°F (Jul 29) 94°F 73°F
4 Jun 17, 1910 – Jun 26, 1910 10 95°F (Jun 23) 92°F 66°F
5 Jun 23, 1931 – Jul 1, 1931 9 103°F (Jun 28) 100°F 77°F
6 Jul 27, 1988 – Aug 4, 1988 9 101°F (Jul 31) 97°F 68°F
7 Jul 22, 1916 – Jul 30, 1916 9 100°F (Jul 28) 97°F 74°F
8 Jun 19, 1874 – Jun 27, 1874 9 98°F (Jun 24) 94°F 75°F
9 Aug 25, 1953 – Sep 2, 1953 9 96°F (Aug 31) 93°F 65°F
10 Aug 3, 1900 – Aug 11, 1900 9 95°F (Aug 5) 92°F 72°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

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

54
2026 total
above-normal nights
44.6
Avg / summer
1970–2020
75
Most in a summer
1943

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 (1873–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1873, annual totals have trended +0.41" per decade, about +6.2" 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 Dubuque is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

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

Precipitation, Year to Date

31.66"
2026 YTD
Normal: 28.75"
+2.91"
0.72"
September so far
September normal: 3.82"
-3.10"
10
2026 heavy rain days
Days with ≥ 1.0"

Accumulation vs. Normal

Running total since Jan 1 against the normal pace for the same date · Dubuque is 2.91" ahead of the normal pace

Period Review — Jun 1 – Aug 31, 2026

Any window, evaluated against every other year on record — 92 days

Quick picks: Last 7 days Last 30 days Last 90 days This month
Seasons: Spring (Mar–May) Summer (Jun–Aug) Fall (Sep–Nov)
71.8°F
Average temperature
60th-warmest of 153
+1.6°
vs. average
Normal: 70.2°F (1991–2020)
16.63"
Precipitation
28th-wettest of 149
+2.46"
vs. average
Normal: 14.17" · 117% of normal

Average Temperature by Year — Jun 1 – Aug 31

1874–2026 · 2026 highlighted · trend -0.14° per decade (cooling since 1874)

Precipitation by Year — Jun 1 – Aug 31

1874–2026 · 2026 highlighted · trend +0.19" per decade (wetter since 1874)

Warmest Jun 1 – Aug 31 on Record

# Year Avg Temp
1 1901 76.1°F
2 1936 75.5°F
3 1931 75.4°F
4 1894 75.3°F
5 1921 75.2°F
6 1934 75.2°F
7 1949 74.9°F
8 1874 74.7°F
9 1933 74.5°F
10 1943 74.2°F

Coolest Jun 1 – Aug 31 on Record

# Year Avg Temp
1 1992 65.9°F
2 2009 66.6°F
3 1915 66.6°F
4 2004 66.8°F
5 1951 67.2°F
6 1958 67.3°F
7 1967 67.8°F
8 1985 68.0°F
9 1974 68.3°F
10 1903 68.5°F

Wettest Jun 1 – Aug 31 on Record

# Year Total
1 1993 24.59"
2 2010 24.02"
3 2011 22.82"
4 2002 22.25"
5 1876 21.95"
6 1892 21.75"
7 1925 20.64"
8 1881 20.55"
9 1944 20.55"
10 1885 20.53"

Driest Jun 1 – Aug 31 on Record

# Year Total
1 1886 2.27"
2 1894 3.59"
3 1901 3.79"
4 1927 4.62"
5 1904 5.18"
6 1995 5.67"
7 1895 5.80"
8 2012 5.89"
9 1988 6.40"
10 1985 6.72"
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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