Duluth, MN

Minnesota · Records since 1874–2026

☀️ 81°F Feels like 78°
Currently in Duluth
As of 1:00 PM CDT

Records for September 11

🔥 Record High

92°F

September 11, 1931

+23° from 69° normal

❄ Record Low

31°F

September 11, 1965

-18° from 49° normal
🌞 Normal high: 69°F 🌑 Normal low: 49°F 1991–2020 normals

All-Time Records — Duluth

🔥
106°F
Hottest Day Ever
Jul 13, 1936
❄
-41°F
Coldest Day Ever
Jan 2, 1885
🌧
5.20"
Wettest Day Ever
Jul 21, 1909
☃
24.1"
Most Snow in One Day
Nov 1, 1991

First & Last Dates — Duluth

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)
195 days
Longest growing season
1894
85 days
Shortest growing season
1986
138 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 11

# Temp Date
🏆 92°F September 11, 1931
2 86°F September 11, 1976
3 85°F September 11, 2005
4 84°F September 11, 2024
5 84°F September 11, 2011
6 84°F September 11, 1998
7 83°F September 11, 2012
8 83°F September 11, 1930
9 82°F September 11, 1952
10 82°F September 11, 1948

Top 5 Record Lows — September 11

# Temp Date
🥶 31°F September 11, 1965
2 32°F September 11, 1955
3 33°F September 11, 1985
4 34°F September 11, 1964
5 36°F September 11, 1958
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 — Duluth

threshold: 84°F (90th percentile of historical Jun–Aug highs)
3.8
Avg heat wave length
days (historical)
90°
Avg peak temp
during heat waves
4
Dangerous nights 2026
Overnights ≥ 70°F
1
Heat waves 2026
so far

Days ≥ 90°F Per Year

1874–2026
4
2026 so far
3
Avg/year 1970–2025
3
Avg/year (last 10 complete)
14
Most in a year (1936)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Duluth

# Dates Days Peak Avg High Avg Overnight Low
🏆 Aug 1, 1930 – Aug 8, 1930 8 97°F (Aug 1) 91°F 65°F
2 Jul 1, 2020 – Jul 8, 2020 8 93°F (Jul 2) 88°F 62°F
3 Aug 1, 1878 – Aug 8, 1878 8 92°F (Aug 7) 87°F 66°F
4 Jul 7, 1936 – Jul 13, 1936 7 106°F (Jul 13) 99°F 71°F
5 Aug 22, 1969 – Aug 28, 1969 7 90°F (Aug 28) 86°F 58°F
6 Jul 4, 1988 – Jul 9, 1988 6 97°F (Jul 7) 90°F 63°F
7 Jul 23, 2006 – Jul 28, 2006 6 97°F (Jul 28) 88°F 62°F
8 Jul 12, 2006 – Jul 17, 2006 6 96°F (Jul 15) 89°F 64°F
9 Jun 8, 1956 – Jun 13, 1956 6 92°F (Jun 10) 89°F 59°F
10 Jul 11, 2012 – Jul 16, 2012 6 92°F (Jul 16) 88°F 64°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
39.7
Avg / summer
1970–2020
67
Most in a summer
1878

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 (1871–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1871, annual totals have trended +0.18" per decade, about +2.7" 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 Duluth is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

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

Precipitation, Year to Date

21.56"
2026 YTD
Normal: 22.55"
-0.99"
2.00"
September so far
September normal: 3.48"
-1.48"
5
2026 heavy rain days
Days with ≥ 1.0"

Accumulation vs. Normal

Running total since Jan 1 against the normal pace for the same date · Duluth is 0.99" 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)
65.4°F
Average temperature
23rd-warmest of 153
+2.0°
vs. average
Normal: 63.3°F (1991–2020)
4.02"
Precipitation
50th-wettest of 153
+0.25"
vs. average
Normal: 3.77" · 107% of normal

Average Temperature by Year — Aug 11 – Sep 10

1874–2026 · 2026 highlighted

Precipitation by Year — Aug 11 – Sep 10

1872–2026 · 2026 highlighted · trend +0.05" per decade (wetter since 1872)

Warmest Aug 11 – Sep 10 on Record

# Year Avg Temp
1 2013 69.0°F
2 1983 68.4°F
3 1901 67.3°F
4 1948 67.1°F
5 1877 67.0°F
6 1900 66.8°F
7 1937 66.8°F
8 1947 66.7°F
9 2003 66.4°F
10 1969 66.4°F

Coolest Aug 11 – Sep 10 on Record

# Year Avg Temp
1 1974 56.4°F
2 1964 57.0°F
3 1985 57.0°F
4 1977 57.0°F
5 1914 57.5°F
6 1917 57.6°F
7 1986 57.6°F
8 1885 57.7°F
9 1968 57.8°F
10 1975 57.8°F

Wettest Aug 11 – Sep 10 on Record

# Year Total
1 1964 9.80"
2 1990 9.24"
3 1991 9.04"
4 1999 8.94"
5 1972 8.73"
6 1980 8.04"
7 1881 7.96"
8 1941 7.89"
9 1951 7.82"
10 1973 7.56"

Driest Aug 11 – Sep 10 on Record

# Year Total
1 1976 0.57"
2 2012 0.65"
3 1893 0.72"
4 2005 0.83"
5 1915 0.85"
6 1901 0.87"
7 1981 1.00"
8 1894 1.13"
9 1931 1.14"
10 2006 1.15"
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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