Photo: Chris Pruitt · CC BY-SA 3.0Charleston’s winters are milder and less snowy than most of the U.S.
A typical July afternoon reaches 90°, a January night drops to 40°, and snow is almost unheard of.
A year in Charleston at a glance
Each month’s typical high and low, and what it brings.
What stands out about Charleston’s climate
Compared with towns across the U.S., with Charleston’s place in South Carolina beside it.
What a year in Charleston feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 321 frost-free days a year
In half of years the last 32° night comes by February 4 and the first by December 30. Frost and day counts come from NOAA’s station at Charleston City, SC, 4 miles from the city’s center point, at about the same height.
The 2023 USDA map puts Charleston’s center in zone 9a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 23°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 49 inches of rain a year
August is the wettest month and November the driest. Rain falls on about 114 days a year. Snow is rare: about 0.3" in a normal year at Charleston International Airport, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Charleston
40% of the work is heating, so air conditioning is the bigger bill. Months averaging under 55° run from December through February.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Charleston City, SC.
Living with Charleston’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
321 frost-free days in zone 9a. The last frost comes by Feb 4 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Dec 30.
Months with highs of 62–84° and lows of 40° or more: February, March, April, May, October, November and December. 89 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Charleston from natural hazards, hurricanes are the largest share (54%); heat waves, cold waves, winter storms and ice storms together are 2%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Charleston and its neighbors
Goose Creek has the coldest January nights next door (38°, 2° colder) and North Charleston the hottest July afternoons (92°, 1° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Charleston’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Charleston, SC | 40° | 90° | 49" | 0.3" |
| Moultrie, GA | 39° | 91° | 51" | 0.0" |
| Macclenny, FL | 41° | 92° | 52" | 0.0" |
| Eufaula, AL | 37° | 92° | 52" | 0.5" |
| Rusk, TX | 38° | 93° | 49" | 0.1" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
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°).
A bigger shift than in 54% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods. In a city of 159,000 people, part of the change is the city itself: pavement and buildings hold heat (the urban heat island).
How Charleston compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Charleston’s place among South Carolina’s.
Charleston weather by month
Highs, lows and precipitation from NOAA’s grid at Charleston’s center; snow, wet days and snow on the ground from Charleston International Airport. 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" | 0.0" | 8 | 0 | 53° – 65° |
| April | 75° | 55° | 3.3" | 0.0" | 8 | 0 | 60° – 69° |
| May | 82° | 63° | 3.1" | 0.0" | 8 | 0 | 69° – 77° |
| June | 87° | 71° | 5.5" | 0.0" | 12 | 0 | 75° – 83° |
| July | 90° | 74° | 5.7" | 0.0" | 13 | 0 | 80° – 85° |
| August | 89° | 73° | 6.3" | 0.0" | 13 | 0 | 79° – 83° |
| September | 85° | 69° | 5.3" | 0.0" | 10 | 0 | 74° – 81° |
| October | 78° | 59° | 4.4" | 0.0" | 7 | 0 | 65° – 72° |
| November | 69° | 48° | 2.8" | 0.0" | 7 | 0 | 54° – 65° |
| December | 62° | 43° | 3.3" | 0.0" | 9 | 0 | 43° – 63° |
| Year | 76° | 57° | 49.4" | 0.3" | 114 | 0 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 43° to 63°. August is the most reliable, staying within 5°.
Where Charleston’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Charleston’s center.
- Snow: Charleston International Airport.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Charleston City, SC, 4 miles from the city’s center point, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Charleston’s climate
What is the weather like in Charleston?
A typical July afternoon reaches 90°, a January night drops to 40°, and snow is almost unheard of. Milder January nights than 88% of U.S. towns; hotter July afternoons than 79% of U.S. towns.
How cold does it get in Charleston in winter?
January nights average 40°. About 6 nights a year reach 32° or below. In the coldest January of the last 30 years the month averaged 45°.
How much snow does Charleston get?
About 0.3 inches in a normal winter at Charleston International Airport, so most winters see none.
How hot does it get in Charleston?
July, with a typical high of 90° and a low of 74°. About 25 days a year reach 90° (Charleston City, SC).
When is the first and last frost in Charleston?
In half of years the last spring frost (32°) comes by February 4 and the first fall frost by December 30, about 321 frost-free days, at Charleston City, SC.
What growing zone is Charleston in?
Zone 9a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 23°.
What is the best time of year to visit Charleston?
By one simple rule (highs of 62–84° and lows of 40° or more), February, March, April, May, October, November and December. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Charleston getting warmer?
Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 54% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Charleston.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.