Charleston Downtown, SC

South Carolina · Records since 1893–2026

☁️ 87°F Feels like 93°
Currently in Charleston Downtown
As of 2:30 PM EDT

Records for September 11

🔥 Record High

98°F

September 11, 1985

+14° from 84° normal

❄ Record Low

59°F

September 11, 1956

-15° from 74° normal
🌞 Normal high: 84°F 🌑 Normal low: 74°F 1991–2020 normals

All-Time Records — Charleston Downtown

🔥
104°F
Hottest Day Ever
Jun 2, 1985
❄
7°F
Coldest Day Ever
Feb 14, 1899
🌧
10.38"
Wettest Day Ever
Jun 11, 1973
☃
3.2"
Most Snow in One Day
Feb 13, 1899

First & Last Dates — Charleston Downtown

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)
353 days
Longest growing season
1999
243 days
Shortest growing season
1914

Top 10 Record Highs — September 11

# Temp Date
🏆 98°F September 11, 1985
2 95°F September 11, 1915
3 95°F September 11, 1911
4 94°F September 11, 1933
5 94°F September 11, 1894
6 93°F September 11, 1983
7 93°F September 11, 1927
8 92°F September 11, 1992
9 92°F September 11, 1939
10 91°F September 11, 1991

Top 5 Record Lows — September 11

# Temp Date
🥶 59°F September 11, 1956
2 60°F September 11, 1917
3 60°F September 11, 1914
4 61°F September 11, 1976
5 62°F September 11, 1969
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 1893–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Charleston Downtown

threshold: 93°F (90th percentile of historical Jun–Aug highs)
3.9
Avg heat wave length
days (historical)
97°
Avg peak temp
during heat waves
115
Dangerous nights 2026
Overnights ≥ 70°F
2
Heat waves 2026
so far

Days ≥ 90°F Per Year

1893–2026
38
2026 so far
30
Avg/year 1970–2025
24
Avg/year (last 10 complete)
71
Most in a year (1998)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Charleston Downtown

# Dates Days Peak Avg High Avg Overnight Low
🏆 Jul 20, 1999 – Aug 2, 1999 14 103°F (Aug 1) 96°F 82°F
2 Jun 23, 1952 – Jun 30, 1952 8 103°F (Jun 26) 98°F 80°F
3 Sep 1, 1944 – Sep 7, 1944 7 100°F (Sep 4) 96°F 76°F
4 Jun 21, 1950 – Jun 27, 1950 7 99°F (Jun 24) 97°F 79°F
5 Jun 25, 1977 – Jul 1, 1977 7 99°F (Jun 28) 96°F 76°F
6 Jul 6, 1977 – Jul 12, 1977 7 99°F (Jul 9) 97°F 80°F
7 Jul 29, 1970 – Aug 4, 1970 7 98°F (Aug 1) 95°F 78°F
8 Aug 20, 1968 – Aug 26, 1968 7 97°F (Aug 24) 94°F 80°F
9 Aug 4, 1984 – Aug 10, 1984 7 96°F (Aug 7) 94°F 77°F
10 Jun 26, 1902 – Jul 1, 1902 6 101°F (Jul 1) 97°F 79°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

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

64
2026 total
above-normal nights
37.6
Avg / summer
1970–2020
78
Most in a summer
1998

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 (1893–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1893, annual totals have trended +0.18" per decade, about +2.3" 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 Downtown is tracking against normal, year to date

Daily High Temperature vs Normal

Above normal Below normal

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

Precipitation, Year to Date

18.18"
2026 YTD
Normal: 31.62"
-13.44"
0.03"
September so far
September normal: 5.25"
-5.22"
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 Downtown is 13.44" 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)
83.8°F
Average temperature
3rd-warmest of 134
+2.9°
vs. average
Normal: 80.9°F (1991–2020)
2.99"
Precipitation
28th-driest of 131
-3.57"
vs. average
Normal: 6.56" · 46% of normal

Average Temperature by Year — Aug 11 – Sep 10

1893–2026 · 2026 highlighted · trend +0.06° per decade (warming since 1893)

Precipitation by Year — Aug 11 – Sep 10

1893–2026 · 2026 highlighted · trend +0.11" per decade (wetter since 1893)

Warmest Aug 11 – Sep 10 on Record

# Year Avg Temp
1 1998 84.1°F
2 2021 83.8°F
3 2026 83.8°F
4 1900 83.7°F
5 1985 83.5°F
6 2023 83.0°F
7 1926 82.9°F
8 1975 82.9°F
9 1999 82.8°F
10 2014 82.6°F

Coolest Aug 11 – Sep 10 on Record

# Year Avg Temp
1 1967 77.0°F
2 1986 77.4°F
3 1981 77.6°F
4 1969 78.0°F
5 1976 78.0°F
6 1927 78.1°F
7 1946 78.1°F
8 1972 78.1°F
9 1922 78.3°F
10 1974 78.4°F

Wettest Aug 11 – Sep 10 on Record

# Year Total
1 1933 19.84"
2 1987 18.81"
3 1945 17.61"
4 1988 17.20"
5 1940 16.64"
6 1893 15.85"
7 2004 15.59"
8 1949 15.39"
9 1935 14.44"
10 1992 14.15"

Driest Aug 11 – Sep 10 on Record

# Year Total
1 1997 0.52"
2 1924 0.72"
3 1980 0.86"
4 1954 0.86"
5 1938 1.14"
6 1900 1.17"
7 2018 1.43"
8 1914 1.44"
9 1925 1.55"
10 1930 1.91"
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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