Wilmington, DE

Delaware · Records since 1894–2026

🌤️ 80°F
Currently in Wilmington
As of 2:30 PM EDT

Records for September 7

🔥 Record High

95°F

September 7, 1983

+14° from 81° normal

❄ Record Low

43°F

September 7, 1984

-19° from 62° normal
🌞 Normal high: 81°F 🌑 Normal low: 62°F 1991–2020 normals

All-Time Records — Wilmington

🔥
107°F
Hottest Day Ever
Aug 7, 1918
❄
-15°F
Coldest Day Ever
Feb 9, 1934
🌧
8.29"
Wettest Day Ever
Sep 16, 1999
☃
22.0"
Most Snow in One Day
Jan 7, 1996

Top 10 Record Highs — September 7

# Temp Date
🏆 95°F September 7, 1983
2 93°F September 7, 2023
3 93°F September 7, 1954
4 92°F September 7, 2016
5 92°F September 7, 1943
6 92°F September 7, 1922
7 91°F September 7, 2015
8 91°F September 7, 1985
9 90°F September 7, 2010
10 90°F September 7, 1998

Top 5 Record Lows — September 7

# Temp Date
🥶 43°F September 7, 1984
2 47°F September 7, 2000
3 48°F September 7, 2013
4 48°F September 7, 1924
5 49°F September 7, 1988
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 1894–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Wilmington

threshold: 92°F (90th percentile of historical Jun–Aug highs)
4.2
Avg heat wave length
days (historical)
97°
Avg peak temp
during heat waves
36
Dangerous nights 2026
Overnights ≥ 70°F
2
Heat waves 2026
so far

2026 Daily High Temperature vs Normal

Year to date
Above normal Below normal

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

Days ≥ 90°F Per Year

1894–2026
30
2026 so far
21
Avg/year 1970–2025
29
Avg/year (last 10 complete)
59
Most in a year (1895)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Wilmington

# Dates Days Peak Avg High Avg Overnight Low
🏆 Aug 3, 1896 – Aug 13, 1896 11 103°F (Aug 6) 99°F 75°F
2 Aug 26, 1953 – Sep 5, 1953 11 101°F (Aug 30) 97°F 69°F
3 Jul 25, 1894 – Aug 3, 1894 10 101°F (Jul 28) 96°F 73°F
4 Jul 12, 1894 – Jul 21, 1894 10 98°F (Jul 13) 95°F 72°F
5 Aug 5, 1895 – Aug 12, 1895 8 101°F (Aug 11) 96°F 71°F
6 Aug 3, 1930 – Aug 10, 1930 8 98°F (Aug 5) 95°F 71°F
7 Jul 19, 1987 – Jul 26, 1987 8 98°F (Jul 21) 95°F 73°F
8 Jul 7, 1993 – Jul 14, 1993 8 98°F (Jul 8) 96°F 76°F
9 Jul 28, 2002 – Aug 4, 2002 8 98°F (Aug 1) 95°F 72°F
10 Jul 25, 1940 – Jul 31, 1940 7 102°F (Jul 31) 97°F 71°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

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

52
2026 total
above-normal nights
44.4
Avg / summer
1970–2020
67
Most in a summer
1973

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

32.17"
2026 YTD
Normal: 31.15"
+1.02"
1.73"
September so far
September normal: 4.38"
-2.65"
7
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 · Wilmington is 1.02" ahead of the normal pace

Monthly Precipitation — Last 24 Months

Blue = actual · dashed line = monthly normal

Annual Precipitation Per Year (1894–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1894, annual totals have trended +0.26" per decade, about +3.4" 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

77.3°F

Average temperature · August 2026

49th-warmest month on record

13th-warmest August of 113 on record

+1.7° vs. 75.6° average (1991–2020)
81.2°F
Warmest month ever
July 1955
79.2°F
Warmest August ever
2016
6
Days ≥ 90°F
in August
103°F
Hottest of 2026
Jul 2

Longest 90°F Streak in August

5 consecutive days with highs of at least 90°F (Aug 6–10, 2026, peaking at 93°F)

Ties the longest August streak since 2022 (4 years). The August record is 16 days, set in 1895.

Average August Temperature by Year

1894–2026 · 2026 highlighted · trend +0.22° per decade (warming since 1894)

Precipitation — August 2026

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

5.82"
Total precipitation
August 2026
+1.84"
vs. average
Normal: 3.98" · 146% of normal
28th-wettest
August rank
of 127 on record
14.91"
Wettest August ever
1911 · driest 0.25" (1972)

August Precipitation by Year

1895–2026 · 2026 highlighted · trend -0.10" per decade (drier since 1895)

Wettest Augusts on Record

# Year Total
1 1911 14.91"
2 2011 14.70"
3 1955 12.09"
4 1967 11.16"
5 1933 11.10"
6 1906 10.70"
7 1945 10.67"
8 1942 9.54"
9 2020 9.36"
10 1901 8.73"

Driest Augusts on Record

# Year Total
1 1972 0.25"
2 1896 0.47"
3 1916 0.60"
4 1980 1.09"
5 1943 1.12"
6 2008 1.16"
7 1968 1.17"
8 1983 1.29"
9 2010 1.34"
10 1930 1.34"

Warmest Augusts on Record

# Year Avg Temp
1 2016 79.2°F
2 2022 78.9°F
3 1895 78.8°F
4 1980 78.2°F
5 2018 78.2°F
6 2021 78.2°F
7 1973 78.0°F
8 2005 77.9°F
9 1955 77.9°F
10 1896 77.8°F

Warmest Months on Record (Any Month)

# Month Avg Temp
1 July 1955 81.2°F
2 July 2011 80.8°F
3 July 2012 80.3°F
4 July 2025 80.3°F
5 July 1894 80.1°F
6 July 2020 80.0°F
7 July 2023 80.0°F
8 July 1999 80.0°F
9 July 1896 80.0°F
10 July 2019 79.8°F

Nearby Stations — August 2026

How the same month ranked at the closest reporting stations

Station Avg Temp August Rank
Wilmington, DE 77.3°F 13th of 113
Philadelphia Center City, PA 79.7°F 13th of 87
Philadelphia, PA 79.2°F 8th of 153
Reading, PA 74.6°F 44th of 131
Trenton, NJ 75.2°F 43rd of 133
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 1,341 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 127 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 1
so far
 Aug 31 Jun 9, 2004 Oct 7, 2007 +0.2 d/decade
Last 80°F day
The last genuinely warm afternoon
 Sep 6
so far
 Oct 8 Sep 11, 1966 Nov 15, 1993 +0.8 d/decade
First high below 50°F
The first afternoon that stays cold
 not yet Nov 7 Oct 10, 1979 Nov 28, 1948 +0.7 d/decade
First 32°F freeze
Growing season over
 not yet Nov 2 Sep 27, 1940 Nov 24, 1985 +0.5 d/decade
First 28°F hard freeze
Cold enough to end tender growth
 not yet Nov 12 Oct 18, 1982 Dec 2, 1985 +0.1 d/decade
First 20°F night
Winter cold arriving
 not yet Dec 9 Nov 11, 2017 Dec 30, 2001 +0.3 d/decade
First measurable snow
0.1" or more in a day
 not yet Dec 7 Oct 10, 1979 Dec 29, 2012 +0.4 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 1894 · trending +0.5 days later per decade

208
Normal length
1991–2020 average
234
Longest on record
2005
144
Shortest on record
1947

Growing Season Length by Year

Days between the last spring freeze and the first fall freeze · trending +1.4 days longer per decade

Fall Average Temperature by Year

1895–2025 · 2026 highlighted · trend +0.12° per decade (warming since 1895)

Fall Precipitation by Year

1897–2025 · 2026 highlighted · trend +0.11" per decade (wetter since 1897)

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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