Climateby Month

Charleston, SC climate by month

NOAA 1991-2020 normals · 10 ft elevation

Charleston has hot and oppressively humid summers and cool winters. Highs peak at 88°F in July and fall to 58°F in January. Wet days are spread through the year, from about 6 to 12 a month. Snow is rare. By our comfort score the best month is April.

Warmest month
88°F
July normal high
Coldest month
44°F
January normal low
Wet days a year
102
44.3 in of precipitation
Muggy days a year
137
dew point 65°F or higher

How warm is Charleston?

Normal highs range from 58°F in January to 88°F in July.

40°50°60°70°80°90° January: normal high 58°F (14°C), low 44°F (7°C) 58° 44° February: normal high 60°F (16°C), low 46°F (8°C) March: normal high 66°F (19°C), low 52°F (11°C) April: normal high 72°F (22°C), low 60°F (16°C) May: normal high 79°F (26°C), low 68°F (20°C) June: normal high 84°F (29°C), low 74°F (23°C) July: normal high 88°F (31°C), low 77°F (25°C) 88° 77° August: normal high 86°F (30°C), low 77°F (25°C) September: normal high 83°F (28°C), low 73°F (23°C) October: normal high 76°F (24°C), low 63°F (17°C) November: normal high 67°F (19°C), low 53°F (12°C) December: normal high 61°F (16°C), low 47°F (8°C) JFMAMJJASOND

Bars run from the normal low to the normal high for each month.

How rainy is Charleston?

August has the most wet days (about 12); the year brings about 44 in of precipitation.

January: 8 wet days February: 8 wet days March: 8 wet days April: 7 wet days May: 7 wet days June: 11 wet days July: 12 wet days August: 12 wet days 12 September: 9 wet days October: 7 wet days November: 6 wet days 6 December: 9 wet days JFMAMJJASOND

Wet day: at least 0.01 in of rain or melted snow, counted from daily records 1991-2020.

How humid is Charleston?

Muggy days peak in July, at about 30 days.

January: 0 muggy days February: 0 muggy days 0 March: 0 muggy days April: 3 muggy days May: 13 muggy days June: 26 muggy days July: 30 muggy days 30 August: 30 muggy days September: 23 muggy days October: 9 muggy days November: 3 muggy days December: 1 muggy days JFMAMJJASOND

Muggy day: daily mean dew point of 65°F or higher, from hourly observations 1991-2020 at Charleston AFB/International Airport, 11 mi NW of the city center.

How much daylight?

Daylight ranges from about 10.0 hours in December to 14.3 hours in June.

January: 10.3 hours of daylight February: 11.0 hours of daylight March: 12.0 hours of daylight April: 13.0 hours of daylight May: 13.8 hours of daylight June: 14.3 hours of daylight 14.3 July: 14.1 hours of daylight August: 13.3 hours of daylight September: 12.4 hours of daylight October: 11.4 hours of daylight November: 10.5 hours of daylight December: 10.0 hours of daylight 10.0 JFMAMJJASOND
See all numbers
Monthly climate normals and day counts for Charleston, 1991-2020
MonthHighLowPrecip.Wet daysSnowMuggy daysDaylight
January 58°F44°F 2.6 in8 0.2 in 0 10.3 h
February 60°F46°F 2.6 in8 0.1 in 0 11.0 h
March 66°F52°F 3.0 in8 0.0 in 0 12.0 h
April 72°F60°F 3.0 in7 0.0 in 3 13.0 h
May 79°F68°F 2.6 in7 0.0 in 13 13.8 h
June 84°F74°F 4.8 in11 0.0 in 26 14.3 h
July 88°F77°F 5.1 in12 0.0 in 30 14.1 h
August 86°F77°F 6.1 in12 0.0 in 30 13.3 h
September 83°F73°F 5.3 in9 0.0 in 23 12.4 h
October 76°F63°F 4.1 in7 0.0 in 9 11.4 h
November 67°F53°F 2.3 in6 0.0 in 3 10.5 h
December 61°F47°F 2.9 in9 0.0 in 1 10.0 h

High and low: NOAA 1991-2020 normal daily high and low. Wet days: at least 0.01 in of rain or melted snow. Muggy days: daily mean dew point 65°F or higher.

Best months to visit Charleston

By our comfort score, the best month is April.

Comfort score by month (0-100) and its parts, in days per month
MonthScoreComfortableNotable rainHot or cold
Jan 53751
Feb 57850
Mar 671550
Apr 731650
May 64841
Jun 51175
Jul 46089
Aug 45087
Sep 51362
Oct 641350
Nov 641440
Dec 55950

Score = 40 × share of comfortable days + 25 × share of days without notable rain + 20 × share of days neither hot (90°F+) nor cold (high 40°F or below) + 15 × daylight. How the score works.

Frost dates in Charleston

The last spring frost typically comes around Feb 4, and the first fall frost around Dec 30, leaving 321 frost-free days in a typical year.

Frost and freeze dates for Charleston
Typical date1 year in 10
Last spring frost (32°F)Feb 4after Mar 4
First fall frost (32°F)Dec 30before Dec 2
Last hard freeze (28°F)Jan 24after Feb 20
First hard freeze (28°F)Jan 8before Dec 15
Frost-free season321 daysunder 289 days

"Typical" is the date with a 50% chance of a later spring frost (or earlier fall frost). Planting after the "1 year in 10" spring date gives a 90% chance of no further frost. The Old Farmer's Almanac publishes 30% dates, which fall between our typical and 1-in-10 dates.

Station: Charleston City (USW00013782), NOAA 1991-2020 freeze probabilities. Frost dates for every city in South Carolina.

Hottest and coldest readings, 1991-2020

The highest reading was 103°F (August 1, 1999); the lowest was 19°F (February 5, 1996).

From the temperature station's daily records with NOAA quality flags removed. Not an all-time record.

Near Charleston

Similar climates elsewhere

Where the numbers come from

  • Temperature, rain and frost dates: Charleston City (USW00013782), 0.2 mi NNW of the city center, 10 ft . NOAA normals and daily records, 1991-2020.
  • Snowfall, snow depth, humidity and wind by hour and cloud cover: Charleston Intl Airport (USW00013880), 11 mi NW of the city center, 40 ft . NOAA normals and daily records, 1991-2020.
  • Daily humidity and wind: Charleston AFB/International Airport (722080-13880), 11 mi NW of the city center, 39 ft . Hourly observations, 1991-2020.

Distances from the city center (USGS). Methodology · Report an error