Charleston, SC climate
Charleston has mild winters and warm summers, with plenty of rain. A typical July afternoon reaches 90°, a January night drops to 40°, and snow is almost unheard of.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Charleston feels like
Winter
Spring
Summer
Fall
Charleston weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 60° | 40° | 3.3" | 0.2" | 9 | 0 | 45° – 56° |
| February | 62° | 42° | 3.1" | 0.1" | 9 | 0 | 45° – 60° |
| March | 68° | 48° | 3.4" | 0 | 8 | 0 | 53° – 65° |
| April | 75° | 55° | 3.3" | 0 | 8 | 0 | 60° – 69° |
| May | 82° | 63° | 3.1" | 0 | 8 | 0 | 69° – 77° |
| June | 87° | 71° | 5.5" | 0 | 12 | 0 | 75° – 83° |
| July | 90° | 74° | 5.7" | 0 | 13 | 0 | 80° – 85° |
| August | 89° | 73° | 6.3" | 0 | 13 | 0 | 79° – 83° |
| September | 85° | 69° | 5.3" | 0 | 10 | 0 | 74° – 81° |
| October | 78° | 59° | 4.4" | 0 | 7 | 0 | 65° – 72° |
| November | 69° | 48° | 2.8" | 0 | 7 | 0 | 54° – 65° |
| December | 62° | 43° | 3.3" | 0 | 9 | 0 | 43° – 63° |
| Year | 76° | 57° | 49.4" | 0.3" | 114 | 0 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Charleston
Charleston gets 49 inches of rain and melted snow a year. August is the wettest month and November the driest. Rain or snow falls on about 114 days a year.
About 266 frost-free days a year
In half of years the last 32° night comes by March 7 and the first one by November 27. That leaves about 266 frost-free days for gardens, longer than 92% of U.S. towns.
Heating and cooling a home in Charleston
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Charleston, 43% of that work is heating and 57% is cooling.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Charleston and its neighbors
Charleston borders 7 towns with climate data. January nights across them vary by 3.4°. Goose Creek has the coldest January nights (38°) and North Charleston the hottest July afternoons (92°). Charleston’s January low is 40° and its July high 90°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Charleston compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Charleston averaged 1.4° warmer than the 1900s. The biggest change is in December (+2.7°). The shift is larger than in 65% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Charleston’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. December swings the most: between 1991 and 2020 its average temperature ranged from 43° to 63°. August is the most reliable, staying within 5°.
Common questions about Charleston’s climate
What is the coldest month in Charleston?
January, with a typical high of 60° and a low of 40°.
What is the hottest month in Charleston?
July, with a typical high of 90° and a low of 74°. About 64 days a year reach 90°.
How much snow does Charleston get?
Almost none. A normal year brings 0.3 inches.
When is the first frost in Charleston?
In half of years the first 32° night comes by November 27, and the last spring frost by March 7.
What is the rainiest month in Charleston?
August, with 6.3 inches of rain and melted snow. The year totals 49 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Charleston itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Charleston Intl Airport, SC (6 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.