Charleston weather in May
In May, Charleston sees average daytime highs of 80°F and overnight lows near 66°F, with 2.7 in of rain across 9 wet days and about 13.7 hours of daylight. It is the 5th-warmest and 11th-wettest month of the year here.
Highs climb over the month, from about 77°F in the first days to 83°F by the end. The sky is clear or mostly clear about 41% of the time in May, and the air most often feels muggy.
Daylight stretches from about 13 h 18 min at the start of May to 14 hours by month's end. Set against the rest of the year, May is Charleston's 4th-clearest and 6th-windiest month. For the whole year in context, see Charleston's year-round climate.
- Daytime high
- 80°
- 5th warmest
- Overnight low
- 66°
- 8th coldest
- Rainfall
- 2.7 in
- 9 wet days
- Daylight
- 13 h 42 min
- 5:26 AM – 7:06 PM
- Cloud cover
- 50%
- 4th clearest
- Wind
- 8 mph
- 6th windiest
- Solar energy
- 6.47 kWh/m²
- Travel score
- 6.8
- out of 10
Charleston is largest city in the U.S. state of South Carolina.
- Density
- 470/km²
- people per km²
- Founded
- 1670
Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.
Temperature in May
Highs climb over the month, from about 77°F in the first days to 83°F by the end.
A typical May day in Charleston reaches about 80°F in the afternoon and slips back to 66°F overnight — a 14°F spread between the day's warmth and the night's chill. On most days the high lands between 74°F and 86°F. Set against its neighbours, May runs about 6°F warmer than April and about 5°F cooler than June.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°F) | 77 | 77 | 77 | 77 | 78 | 78 | 78 | 78 | 78 | 79 | 79 | 79 | 79 | 79 | 80 | 80 | 80 | 80 | 80 | 81 | 81 | 81 | 81 | 82 | 82 | 82 | 82 | 82 | 83 | 83 | 83 |
| Avg low (°F) | 62 | 62 | 63 | 63 | 63 | 64 | 64 | 64 | 64 | 65 | 65 | 65 | 65 | 66 | 66 | 66 | 67 | 67 | 67 | 67 | 68 | 68 | 68 | 69 | 69 | 69 | 69 | 70 | 70 | 70 | 71 |
| Avg high (°F) | Avg low (°F) | |
|---|---|---|
| 1 | 77 | 62 |
| 2 | 77 | 62 |
| 3 | 77 | 63 |
| 4 | 77 | 63 |
| 5 | 78 | 63 |
| 6 | 78 | 64 |
| 7 | 78 | 64 |
| 8 | 78 | 64 |
| 9 | 78 | 64 |
| 10 | 79 | 65 |
| 11 | 79 | 65 |
| 12 | 79 | 65 |
| 13 | 79 | 65 |
| 14 | 79 | 66 |
| 15 | 80 | 66 |
| 16 | 80 | 66 |
| 17 | 80 | 67 |
| 18 | 80 | 67 |
| 19 | 80 | 67 |
| 20 | 81 | 67 |
| 21 | 81 | 68 |
| 22 | 81 | 68 |
| 23 | 81 | 68 |
| 24 | 82 | 69 |
| 25 | 82 | 69 |
| 26 | 82 | 69 |
| 27 | 82 | 69 |
| 28 | 82 | 70 |
| 29 | 83 | 70 |
| 30 | 83 | 70 |
| 31 | 83 | 71 |
How May really feels in Charleston
Once humidity and wind are folded in, May averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.
May sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Charleston weather by month
How May compares with the rest of the year at a glance. May is the 5th-warmest and 11th-wettest month here — the current month is highlighted below.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 59° / 43° | 3.2 | 8.4 | 10.1 | 4.8 |
| Feb | 62° / 45° | 3.3 | 7.8 | 10.8 | 5.4 |
| Mar | 67° / 51° | 3.2 | 8.2 | 11.8 | 6.6 |
| Apr | 73° / 58° | 2.9 | 7.5 | 12.8 | 7.4 |
| May | 80° / 66° | 2.7 | 9 | 13.7 | 6.8 |
| Jun | 85° / 73° | 5.1 | 16.3 | 14.1 | 4.5 |
| Jul | 88° / 76° | 5.4 | 17.8 | 13.9 | 3.7 |
| Aug | 87° / 75° | 6.3 | 18.9 | 13.2 | 3.9 |
| Sep | 83° / 71° | 5.1 | 13.3 | 12.2 | 5.5 |
| Oct | 76° / 61° | 4.0 | 7.8 | 11.2 | 7.4 |
| Nov | 67° / 51° | 2.6 | 6.8 | 10.3 | 6.9 |
| Dec | 62° / 46° | 3.4 | 7.7 | 9.9 | 5.5 |
Cloud cover in May
The sky is clear or mostly clear about 41% of the time in May.
Beyond those clear spells, partly cloudy skies cover about 20% of May, with mostly cloudy or overcast conditions the remaining 39%. Skies tend to cloud over as the month goes on.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 63 | 64 | 64 | 64 | 64 | 64 | 64 | 64 | 64 | 64 | 64 | 63 | 63 | 63 | 63 | 63 | 62 | 62 | 61 | 60 | 60 | 60 | 59 | 58 | 58 | 57 | 57 | 56 | 55 | 54 | 54 |
| Cloudier (%) | 37 | 36 | 36 | 36 | 36 | 36 | 36 | 36 | 36 | 36 | 36 | 37 | 37 | 37 | 37 | 37 | 38 | 38 | 39 | 40 | 40 | 40 | 41 | 42 | 42 | 43 | 43 | 44 | 45 | 46 | 46 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| 1 | 63 | 37 |
| 2 | 64 | 36 |
| 3 | 64 | 36 |
| 4 | 64 | 36 |
| 5 | 64 | 36 |
| 6 | 64 | 36 |
| 7 | 64 | 36 |
| 8 | 64 | 36 |
| 9 | 64 | 36 |
| 10 | 64 | 36 |
| 11 | 64 | 36 |
| 12 | 63 | 37 |
| 13 | 63 | 37 |
| 14 | 63 | 37 |
| 15 | 63 | 37 |
| 16 | 63 | 37 |
| 17 | 62 | 38 |
| 18 | 62 | 38 |
| 19 | 61 | 39 |
| 20 | 60 | 40 |
| 21 | 60 | 40 |
| 22 | 60 | 40 |
| 23 | 59 | 41 |
| 24 | 58 | 42 |
| 25 | 58 | 42 |
| 26 | 57 | 43 |
| 27 | 57 | 43 |
| 28 | 56 | 44 |
| 29 | 55 | 45 |
| 30 | 54 | 46 |
| 31 | 54 | 46 |
Chance of precipitation in May
Charleston gets around 2.7 in of rain over 9 wet days in May. The line is the day-by-day chance of measurable precipitation.
Day to day, the chance of measurable rain averages around 30% and peaks near 43% on the wettest days. The odds climb toward the end of the month.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain chance (%) | 24 | 24 | 24 | 24 | 23 | 24 | 24 | 24 | 24 | 25 | 25 | 26 | 26 | 27 | 28 | 28 | 29 | 30 | 31 | 31 | 32 | 33 | 34 | 34 | 35 | 36 | 37 | 38 | 40 | 41 | 43 |
| Rain chance (%) | |
|---|---|
| 1 | 24 |
| 2 | 24 |
| 3 | 24 |
| 4 | 24 |
| 5 | 23 |
| 6 | 24 |
| 7 | 24 |
| 8 | 24 |
| 9 | 24 |
| 10 | 25 |
| 11 | 25 |
| 12 | 26 |
| 13 | 26 |
| 14 | 27 |
| 15 | 28 |
| 16 | 28 |
| 17 | 29 |
| 18 | 30 |
| 19 | 31 |
| 20 | 31 |
| 21 | 32 |
| 22 | 33 |
| 23 | 34 |
| 24 | 34 |
| 25 | 35 |
| 26 | 36 |
| 27 | 37 |
| 28 | 38 |
| 29 | 40 |
| 30 | 41 |
| 31 | 43 |
Humidity in May
Most of May feels muggy — the stacked bands show each day's mix of comfort levels, read off the dew point.
By dew point, May lands in the muggy band about 32% of days. Sticky, muggy-or-worse air turns up on roughly 53% of them.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 16 | 15 | 15 | 14 | 14 | 13 | 13 | 13 | 12 | 11 | 11 | 10 | 9 | 8 | 7 | 7 | 6 | 5 | 4 | 4 | 3 | 2 | 2 |
| Comfortable (%) | 21 | 20 | 20 | 19 | 18 | 18 | 17 | 17 | 16 | 16 | 15 | 14 | 14 | 13 | 12 | 12 | 12 | 12 | 11 | 11 | 11 | 11 | 10 | 10 | 9 | 9 | 9 | 8 | 8 | 7 | 7 |
| Humid (%) | 28 | 28 | 28 | 27 | 27 | 27 | 27 | 26 | 26 | 25 | 25 | 24 | 24 | 23 | 23 | 22 | 22 | 22 | 21 | 21 | 20 | 20 | 20 | 19 | 19 | 18 | 17 | 16 | 16 | 15 | 14 |
| Muggy (%) | 23 | 24 | 26 | 27 | 29 | 30 | 32 | 33 | 34 | 35 | 36 | 37 | 37 | 37 | 37 | 37 | 37 | 37 | 36 | 36 | 35 | 34 | 34 | 33 | 32 | 31 | 30 | 29 | 28 | 27 | 27 |
| Oppressive (%) | 5 | 6 | 6 | 6 | 7 | 7 | 8 | 8 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 16 | 17 | 19 | 21 | 22 | 24 | 27 | 29 | 31 | 34 | 37 | 39 | 42 | 44 | 47 | 49 |
| Miserable (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 |
| Dry (%) | Comfortable (%) | Humid (%) | Muggy (%) | Oppressive (%) | Miserable (%) | |
|---|---|---|---|---|---|---|
| 1 | 23 | 21 | 28 | 23 | 5 | 0 |
| 2 | 22 | 20 | 28 | 24 | 6 | 0 |
| 3 | 21 | 20 | 28 | 26 | 6 | 0 |
| 4 | 20 | 19 | 27 | 27 | 6 | 0 |
| 5 | 19 | 18 | 27 | 29 | 7 | 0 |
| 6 | 18 | 18 | 27 | 30 | 7 | 0 |
| 7 | 17 | 17 | 27 | 32 | 8 | 0 |
| 8 | 16 | 17 | 26 | 33 | 8 | 0 |
| 9 | 16 | 16 | 26 | 34 | 8 | 0 |
| 10 | 15 | 16 | 25 | 35 | 9 | 0 |
| 11 | 15 | 15 | 25 | 36 | 10 | 0 |
| 12 | 14 | 14 | 24 | 37 | 11 | 0 |
| 13 | 14 | 14 | 24 | 37 | 12 | 0 |
| 14 | 13 | 13 | 23 | 37 | 13 | 0 |
| 15 | 13 | 12 | 23 | 37 | 14 | 0 |
| 16 | 13 | 12 | 22 | 37 | 16 | 0 |
| 17 | 12 | 12 | 22 | 37 | 17 | 0 |
| 18 | 11 | 12 | 22 | 37 | 19 | 0 |
| 19 | 11 | 11 | 21 | 36 | 21 | 0 |
| 20 | 10 | 11 | 21 | 36 | 22 | 0 |
| 21 | 9 | 11 | 20 | 35 | 24 | 0 |
| 22 | 8 | 11 | 20 | 34 | 27 | 0 |
| 23 | 7 | 10 | 20 | 34 | 29 | 0 |
| 24 | 7 | 10 | 19 | 33 | 31 | 0 |
| 25 | 6 | 9 | 19 | 32 | 34 | 0 |
| 26 | 5 | 9 | 18 | 31 | 37 | 0 |
| 27 | 4 | 9 | 17 | 30 | 39 | 1 |
| 28 | 4 | 8 | 16 | 29 | 42 | 1 |
| 29 | 3 | 8 | 16 | 28 | 44 | 1 |
| 30 | 2 | 7 | 15 | 27 | 47 | 1 |
| 31 | 2 | 7 | 14 | 27 | 49 | 1 |
Wind in May
Winds average 8 mph in May.
Across May, daily wind ranges from about 8 mph on the calmest days to 9 mph at its breeziest. It stays fairly steady from day to day.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (mph) | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 9 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 | 8 |
| Feels | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze | light breeze |
| Wind speed (mph) | Feels | |
|---|---|---|
| 1 | 9 | light breeze |
| 2 | 9 | light breeze |
| 3 | 9 | light breeze |
| 4 | 9 | light breeze |
| 5 | 9 | light breeze |
| 6 | 9 | light breeze |
| 7 | 9 | light breeze |
| 8 | 9 | light breeze |
| 9 | 8 | light breeze |
| 10 | 8 | light breeze |
| 11 | 8 | light breeze |
| 12 | 8 | light breeze |
| 13 | 8 | light breeze |
| 14 | 8 | light breeze |
| 15 | 8 | light breeze |
| 16 | 8 | light breeze |
| 17 | 8 | light breeze |
| 18 | 8 | light breeze |
| 19 | 8 | light breeze |
| 20 | 8 | light breeze |
| 21 | 8 | light breeze |
| 22 | 8 | light breeze |
| 23 | 8 | light breeze |
| 24 | 8 | light breeze |
| 25 | 8 | light breeze |
| 26 | 8 | light breeze |
| 27 | 8 | light breeze |
| 28 | 8 | light breeze |
| 29 | 8 | light breeze |
| 30 | 8 | light breeze |
| 31 | 8 | light breeze |
Sunrise & sunset in May
Daylight runs from about 13 h 18 min at the start of May to 14 hours by month's end. The lit band spans sunrise to sunset each day.
Days grow by about 42 minutes over May. Sunrise moves from 5:39 AM to 5:18 AM, and sunset from 6:55 PM to 7:17 PM.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 13.3 | 13.3 | 13.3 | 13.4 | 13.4 | 13.4 | 13.4 | 13.5 | 13.5 | 13.5 | 13.6 | 13.6 | 13.6 | 13.6 | 13.7 | 13.7 | 13.7 | 13.7 | 13.7 | 13.8 | 13.8 | 13.8 | 13.8 | 13.9 | 13.9 | 13.9 | 13.9 | 13.9 | 13.9 | 14.0 | 14.0 |
| Sunrise (AM) | 5:39 | 5:38 | 5:37 | 5:36 | 5:35 | 5:34 | 5:33 | 5:32 | 5:31 | 5:30 | 5:29 | 5:29 | 5:28 | 5:27 | 5:26 | 5:26 | 5:25 | 5:24 | 5:24 | 5:23 | 5:22 | 5:22 | 5:21 | 5:21 | 5:20 | 5:20 | 5:19 | 5:19 | 5:18 | 5:18 | 5:18 |
| Sunset (PM) | 6:55 | 6:56 | 6:57 | 6:58 | 6:58 | 6:59 | 7:00 | 7:01 | 7:01 | 7:02 | 7:03 | 7:03 | 7:04 | 7:05 | 7:06 | 7:06 | 7:07 | 7:08 | 7:09 | 7:09 | 7:10 | 7:11 | 7:11 | 7:12 | 7:13 | 7:13 | 7:14 | 7:15 | 7:15 | 7:16 | 7:17 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| 1 | 13.3 | 5:39 | 6:55 |
| 2 | 13.3 | 5:38 | 6:56 |
| 3 | 13.3 | 5:37 | 6:57 |
| 4 | 13.4 | 5:36 | 6:58 |
| 5 | 13.4 | 5:35 | 6:58 |
| 6 | 13.4 | 5:34 | 6:59 |
| 7 | 13.4 | 5:33 | 7:00 |
| 8 | 13.5 | 5:32 | 7:01 |
| 9 | 13.5 | 5:31 | 7:01 |
| 10 | 13.5 | 5:30 | 7:02 |
| 11 | 13.6 | 5:29 | 7:03 |
| 12 | 13.6 | 5:29 | 7:03 |
| 13 | 13.6 | 5:28 | 7:04 |
| 14 | 13.6 | 5:27 | 7:05 |
| 15 | 13.7 | 5:26 | 7:06 |
| 16 | 13.7 | 5:26 | 7:06 |
| 17 | 13.7 | 5:25 | 7:07 |
| 18 | 13.7 | 5:24 | 7:08 |
| 19 | 13.7 | 5:24 | 7:09 |
| 20 | 13.8 | 5:23 | 7:09 |
| 21 | 13.8 | 5:22 | 7:10 |
| 22 | 13.8 | 5:22 | 7:11 |
| 23 | 13.8 | 5:21 | 7:11 |
| 24 | 13.9 | 5:21 | 7:12 |
| 25 | 13.9 | 5:20 | 7:13 |
| 26 | 13.9 | 5:20 | 7:13 |
| 27 | 13.9 | 5:19 | 7:14 |
| 28 | 13.9 | 5:19 | 7:15 |
| 29 | 13.9 | 5:18 | 7:15 |
| 30 | 14.0 | 5:18 | 7:16 |
| 31 | 14.0 | 5:18 | 7:17 |
Solar energy in May
Average shortwave solar energy reaching the ground each day in May, about 6.47 kWh/m² — the sunniest month for solar.
For context, solar energy here swings from a low near 2.62 kWh/m² to a high of 6.47 kWh/m² in May across the year — May's 6.47 kWh/m² sits near the top of that range.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 6.4 | 6.4 | 6.4 | 6.4 | 6.4 | 6.4 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.5 | 6.4 | 6.4 | 6.4 | 6.4 | 6.4 | 6.4 | 6.3 | 6.3 |
| Level | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense | Intense |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| 1 | 6.4 | Intense |
| 2 | 6.4 | Intense |
| 3 | 6.4 | Intense |
| 4 | 6.4 | Intense |
| 5 | 6.4 | Intense |
| 6 | 6.4 | Intense |
| 7 | 6.5 | Intense |
| 8 | 6.5 | Intense |
| 9 | 6.5 | Intense |
| 10 | 6.5 | Intense |
| 11 | 6.5 | Intense |
| 12 | 6.5 | Intense |
| 13 | 6.5 | Intense |
| 14 | 6.5 | Intense |
| 15 | 6.5 | Intense |
| 16 | 6.5 | Intense |
| 17 | 6.5 | Intense |
| 18 | 6.5 | Intense |
| 19 | 6.5 | Intense |
| 20 | 6.5 | Intense |
| 21 | 6.5 | Intense |
| 22 | 6.5 | Intense |
| 23 | 6.5 | Intense |
| 24 | 6.4 | Intense |
| 25 | 6.4 | Intense |
| 26 | 6.4 | Intense |
| 27 | 6.4 | Intense |
| 28 | 6.4 | Intense |
| 29 | 6.4 | Intense |
| 30 | 6.3 | Intense |
| 31 | 6.3 | Intense |
Hazard calendar for Charleston
None of Charleston's seasonal hazards are active in May. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.
Charleston sits in the Atlantic hurricane belt; the season peaks August–October.
Is May a good time to visit Charleston?
Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).
May is a reasonable time to visit Charleston for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Charleston in May
From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In May, Charleston sees daytime highs around 80°F and nights near 66°F. Pack sun protection. Worth having: light clothes and rain gear. About 9 days see rain.
Sea temperature near Charleston in May
The nearest coast averages about 73°F in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 11 mi away) is warmest in August at about 83°F and coldest in February near 60°F.
It's comfortable for a long swim from Apr 25 to Nov 19 — about 6.9 months when the water holds above 68°F.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 61 | 60 | 61 | 66 | 73 | 80 | 83 | 83 | 81 | 75 | 68 | 64 |
| Comfort | Cool | Cool | Cool | Cool | Refreshing | Warm | Tropical | Tropical | Warm | Warm | Refreshing | Cool |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 61 | Cool |
| Feb | 60 | Cool |
| Mar | 61 | Cool |
| Apr | 66 | Cool |
| May | 73 | Refreshing |
| Jun | 80 | Warm |
| Jul | 83 | Tropical |
| Aug | 83 | Tropical |
| Sep | 81 | Warm |
| Oct | 75 | Warm |
| Nov | 68 | Refreshing |
| Dec | 64 | Cool |
UV index in Charleston in May
Clear-sky midday UV in May peaks around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Charleston peaks around July 13 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 3 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 4 | 5 | 7 | 7 | 8 | 9 | 10 | 9 | 8 | 6 | 4 | 3 |
| Level | Moderate | Moderate | High | Very high | Very high | Very high | Very high | Very high | Very high | High | Moderate | Moderate |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 4 | Moderate |
| Feb | 5 | Moderate |
| Mar | 7 | High |
| Apr | 7 | Very high |
| May | 8 | Very high |
| Jun | 9 | Very high |
| Jul | 10 | Very high |
| Aug | 9 | Very high |
| Sep | 8 | Very high |
| Oct | 6 | High |
| Nov | 4 | Moderate |
| Dec | 3 | Moderate |
Air quality in Charleston in May
Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.
Air quality in Charleston is worst in March — around 20 µg/m³ PM2.5 (moderate), about 2.8× the cleanest month (December, 7 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 8 | 12 | 20 | 14 | 13 | 16 | 17 | 15 | 11 | 8 | 8 | 7 |
| Level | Good | Good | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 8 | Good |
| Feb | 12 | Good |
| Mar | 20 | Moderate |
| Apr | 14 | Moderate |
| May | 13 | Moderate |
| Jun | 16 | Moderate |
| Jul | 17 | Moderate |
| Aug | 15 | Moderate |
| Sep | 11 | Good |
| Oct | 8 | Good |
| Nov | 8 | Good |
| Dec | 7 | Good |
Where is Charleston?
Charleston sits at 32.8°N, 79.9°W, 20 ft above sea level, in United States. The nearest listed city is Mount Pleasant, 4.3 mi away.
Topography around Charleston
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Charleston.
Within 2 miles, the terrain around Charleston has only modest variations in elevation — a maximum elevation change of 79 ft around an average of 7 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 131 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 226 ft.
The land around Charleston is covered by water (51%) and artificial surfaces (23%) within 2 miles, water (34%) and trees (33%) within 10 miles, and trees (51%) and water (37%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Charleston (32.7763°, -79.9327°, elevation 20 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).