Charleston, SC

South Carolina · Records since 1937–2026

☁️ 86°F Feels like 92°
Currently in Charleston
As of 2:30 PM EDT

Records for September 11

🔥 Record High

95°F

September 11, 2002

+9° from 86° normal

❄ Record Low

49°F

September 11, 1956

-21° from 70° normal
🌞 Normal high: 86°F 🌑 Normal low: 70°F 1991–2020 normals

All-Time Records — Charleston

🔥
105°F
Hottest Day Ever
Aug 1, 1999
❄
6°F
Coldest Day Ever
Jan 21, 1985
🌧
11.50"
Wettest Day Ever
Oct 3, 2015
☃
6.0"
Most Snow in One Day
Dec 23, 1989

First & Last Dates — Charleston

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)
317 days
Longest growing season
2023
203 days
Shortest growing season
1962
269 days
Normal growing season
1991–2020 average

Top 10 Record Highs — September 11

# Temp Date
🏆 95°F September 11, 2002
2 95°F September 11, 1983
3 94°F September 11, 2016
4 94°F September 11, 1990
5 94°F September 11, 1985
6 93°F September 11, 2023
7 93°F September 11, 1954
8 93°F September 11, 1939
9 92°F September 11, 1987
10 92°F September 11, 1942

Top 5 Record Lows — September 11

# Temp Date
🥶 49°F September 11, 1956
2 52°F September 11, 1976
3 59°F September 11, 1998
4 59°F September 11, 1972
5 60°F September 11, 1981
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 1937–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Charleston

threshold: 95°F (90th percentile of historical Jun–Aug highs)
4.2
Avg heat wave length
days (historical)
98°
Avg peak temp
during heat waves
105
Dangerous nights 2026
Overnights ≥ 70°F
6
Heat waves 2026
so far

Days ≥ 90°F Per Year

1937–2026
81
2026 so far
58
Avg/year 1970–2025
74
Avg/year (last 10 complete)
98
Most in a year (2016)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Charleston

# Dates Days Peak Avg High Avg Overnight Low
🏆 Jul 7, 1986 – Jul 21, 1986 15 104°F (Jul 19) 100°F 78°F
2 Jul 3, 2016 – Jul 15, 2016 13 100°F (Jul 8) 97°F 77°F
3 Aug 10, 2026 – Aug 20, 2026 11 99°F (Aug 13) 97°F 76°F
4 Jun 13, 2015 – Jun 22, 2015 10 99°F (Jun 16) 97°F 77°F
5 Jul 4, 2026 – Jul 12, 2026 9 100°F (Jul 9) 97°F 76°F
6 Jul 26, 1999 – Aug 2, 1999 8 105°F (Aug 1) 99°F 77°F
7 May 24, 2019 – May 31, 2019 8 101°F (May 28) 99°F 74°F
8 Jun 21, 1950 – Jun 28, 1950 8 99°F (Jun 27) 97°F 75°F
9 Aug 12, 1995 – Aug 18, 1995 7 102°F (Aug 14) 99°F 76°F
10 Jun 24, 1952 – Jun 30, 1952 7 101°F (Jun 26) 98°F 75°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

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

65
2026 total
above-normal nights
40.4
Avg / summer
1970–2020
79
Most in a summer
2016

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 (1937–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1937, annual totals have trended +0.27" per decade, about +2.4" 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 Charleston is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

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

Precipitation, Year to Date

21.68"
2026 YTD
Normal: 38.27"
-16.59"
0.41"
September so far
September normal: 6.01"
-5.60"
4
2026 heavy rain days
Days with ≥ 1.0"

Accumulation vs. Normal

Running total since Jan 1 against the normal pace for the same date · Charleston is 16.59" 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)
83.6°F
Average temperature
1st-warmest of 90
+3.1°
vs. average
Normal: 80.5°F (1991–2020)
4.49"
Precipitation
26th-driest of 90
-2.52"
vs. average
Normal: 7.01" · 64% of normal

Average Temperature by Year — Aug 11 – Sep 10

1937–2026 · 2026 highlighted · trend +0.31° per decade (warming since 1937)

Precipitation by Year — Aug 11 – Sep 10

1937–2026 · 2026 highlighted · trend +0.03" per decade (wetter since 1937)

Warmest Aug 11 – Sep 10 on Record

# Year Avg Temp
1 2026 83.6°F
2 2023 83.0°F
3 2014 83.0°F
4 1990 82.8°F
5 1983 82.5°F
6 2018 82.3°F
7 2016 82.3°F
8 2010 82.1°F
9 2020 81.9°F
10 1993 81.8°F

Coolest Aug 11 – Sep 10 on Record

# Year Avg Temp
1 1967 76.1°F
2 1976 76.8°F
3 1969 76.9°F
4 1953 77.1°F
5 1956 77.2°F
6 1946 77.4°F
7 1972 77.5°F
8 1950 77.8°F
9 1986 77.9°F
10 1958 78.0°F

Wettest Aug 11 – Sep 10 on Record

# Year Total
1 1987 17.69"
2 1940 16.10"
3 1988 15.51"
4 1971 14.74"
5 1949 14.49"
6 1943 13.44"
7 1995 13.04"
8 2004 12.80"
9 1986 12.68"
10 1989 12.39"

Driest Aug 11 – Sep 10 on Record

# Year Total
1 2024 0.98"
2 1966 1.09"
3 1954 1.25"
4 1980 1.69"
5 2018 1.80"
6 1990 2.58"
7 1941 2.59"
8 1997 2.61"
9 1975 2.69"
10 1999 2.73"
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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