Charleston, SC weather in May
In May, Charleston sees highs around 79°F and lows around 68°F: mild and often humid, with some rain. Rain falls on about 7 days. Good for outdoor plans.
- Normal high
- 79°F
- Normal low
- 68°F
- Wet days
- 7
- 2.6 in total
- Muggy days
- 13
- dew point 65°F+
How May changes from start to finish
| May 1 | May 31 | |
|---|---|---|
| Normal high | 76°F | 82°F |
| Normal low | 64°F | 72°F |
| Chance of a wet day | 22% | 28% |
| Sunrise / sunset | 6:32 am / 8:01 pm | 6:12 am / 8:22 pm |
| Daylight | 13.5 h | 14.2 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Eastern Time).
A typical May day
- 6 am65°Fdew point 62°F
- 9 am75°Fdew point 62°F
- Noon80°Fdew point 61°F
- 3 pm81°Fdew point 61°F
- 6 pm77°Fdew point 61°F
- 9 pm71°Fdew point 63°F
NOAA hourly normals (local standard time) from Charleston Intl Airport (11 mi away); average wind 8 mph; clear or few clouds in 39% of daytime hours, mostly cloudy or overcast in 36%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F8 of 31
- Beach dayshigh 80-95°F, under 0.05 in of rain, afternoon wind under 15 mph11 of 31
- Hot dayshigh 90°F or more1 of 31
- Muggy daysdaily mean dew point 65°F or more13 of 31
- Wet daysat least 0.01 in of rain or melted snow7 of 31
- Notable rainat least 0.10 in4 of 31
- Freezing nightslow 32°F or below0 of 31
Average days per May, counted from daily records for each year 1991-2020.
Rain in May
Normal precipitation is 2.6 in; a dry May brings about 1.4 in and a wet one about 3.6 in (25th and 75th percentiles). About 2 days bring half an inch or more, and about 1 an inch or more.
How May varies from year to year
- Warmest May, 1991-20201998: average high 85°F
- Coolest May1997: average high 76°F
- Wettest May2017: 6.3 in
- Driest May2000: 0.02 in
- Highest reading100°F (May 27, 2019)
- Lowest reading49°F (May 2, 1999)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
May compared with April and June
| April | May | June | |
|---|---|---|---|
| Normal high | 72°F | 79°F | 84°F |
| Normal low | 60°F | 68°F | 74°F |
| Wet days | 7 | 7 | 11 |
| Comfortable days | 16 | 8 | 1 |
| Daylight | 13.0 h | 13.8 h | 14.3 h |
Highs change by +7°F from April and +5°F into June.
Nearby alternatives in May
- Warmer: Hilton Head Island, SC62 mi · high 84°F · 8 wet days
How Charleston ranks in May
- Normal high150th warmest of 378 cities; 3rd of 5 in South Carolina
- Wet days108th driest of 378
- Comfortable days234th most of 339
What to pack for Charleston in May
- A swimsuit – about 11 beach days
Heating and cooling
May has 6 heating degree days and 269 cooling degree days (base 65°F), 7% of the year's total heating and cooling demand.
Questions
How hot is Charleston in May?
The normal high is 79°F and the normal low is 68°F. From 1991 to 2020 the hottest May reading was 100°F (May 27, 2019).
Does it rain a lot in Charleston in May?
About 7 days in May have at least 0.01 in of precipitation, and the normal total is 2.6 in. The wettest May in 1991-2020 was in 2017 (6.3 in); the driest was in 2000 (0.02 in).
Is May a good time to visit Charleston?
May ranks 3rd of 12 months on our comfort score for Charleston (64 out of 100). It has about 8 comfortable days and about 1 day at 90°F or hotter. The best month is April.
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.