May weather forecastCharleston Heights, SC
May
Weather in May
May, the last month of the spring in Charleston Heights, is another warm month, with an average temperature fluctuating between 66.7°F (19.3°C) and 80.8°F (27.1°C).Temperature
A soft shift in the average high-temperature is noticeable in May, transitioning from 74.1°F (23.4°C) in April to a still moderately hot 80.8°F (27.1°C). Charleston Heights records an average temperature drop to a comfortable 66.7°F (19.3°C) in May.Heat index
In May, the average heat index is evaluated at 84.2°F (29°C). Prolonged exposure and physical activity might induce exhaustion, potentially causing heat cramps.Heat index guidelines indicate values are for light wind scenarios and shaded regions. Being under direct sunlight might amplify the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is a value derived by merging air temperature with the humidity to convey how the climate feels. An individual's perception of weather can be swayed by a variety of elements including metabolic differences, pregnancy status, and their level of physical exertion. One's exposure to direct sunlight has the potential to intensify the heat sensation, increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are largely significant for babies and toddlers. Children usually face more risks than adults as their ability to sweat is less. Additionally, their larger skin surface in relation to their petite bodies and higher heat output due to their activities increases their vulnerability.
Humidity
In May, the average relative humidity is 75%.Rainfall
In Charleston Heights, in May, during 13.4 rainfall days, 1.42" (36mm) of precipitation is typically accumulated. In Charleston Heights, during the entire year, the rain falls for 154.4 days and collects up to 23.43" (595mm) of precipitation.Snowfall
In Charleston Heights, snow does not fall in March through November.Daylight
The average length of the day in May is 13h and 52min.On the first day of May in Charleston Heights, sunrise is at 6:31 am and sunset at 8:02 pm. On the last day of the month, sunrise is at 6:12 am and sunset at 8:22 pm EDT.
Sunshine
In Charleston Heights, the average sunshine in May is 10.4h.UV index
The months with the highest UV index are May through August, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: In May, the maximum UV index of 7 translates into these guidelines:
Resist extreme sun exposure. Guarding against solar damage is essential. Be aware that the sun's UV radiation is strongest between 10 a.m. and 4 p.m. and try to reduce direct sun exposure during this period as much as possible. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Charleston Heights, SC
- Average high temperature in May: 80.8°F
The warmest month (with the highest average high temperature) is July (89.6°F).
The month with the lowest average high temperature is January (56.8°F).
- Average low temperature in May: 66.7°F
The month with the highest average low temperature is July (76.5°F).
The coldest month (with the lowest average low temperature) is January (42.8°F).
Average pressure in May
Charleston Heights, SC
- Average pressure in May: 30.03"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in May
Charleston Heights, SC
- Average wind speed in May: 7.5mph
The windiest month (with the highest average wind speed) is April (8.3mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in May
Charleston Heights, SC
- Average humidity in May: 75%
The month with the highest relative humidity is December (77%).
The month with the lowest relative humidity is March (72%).
Average rainfall in May
Charleston Heights, SC
- Average rainfall in May: 1.42"
The wettest month (with the highest rainfall) is August (4.29").
The driest month (with the least rainfall) is January (0.67").
Average rainfall days in May
Charleston Heights, SC
- Average rainfall days in May: 13.4 days
The month with the highest number of rainy days is August (22.7 days).
The month with the least rainy days is November (6.9 days).
Average snowfall days in May
Charleston Heights, SC
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is December (0.3 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October and November (0 days).
Average daylight in May /
Average sunshine in May
Charleston Heights, SC
- Average daylight in May: 13h and 54min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in May: 10h and 24min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 5h and 36min).
Average sunshine days in May
Charleston Heights, SC
- Average sunshine days in May: 15.8 days
The month with the most sunshine days is November (20.4 days).
The month with the least sunshine days is August (6.1 days).
Average UV index in May
Charleston Heights, SC
- Average UV index in May: 7
The months with the highest UV index are May, June, July and August (UV index 7).
The month with the lowest UV index is January (UV index 3).
Average cloud cover in May
Charleston Heights, SC
- Average cloud cover in May: 29
The month with the most cloud cover is December (Cloud cover 40).
The months with the least cloud cover are June and July (Cloud cover 26).
Average visibility in May
Charleston Heights, SC
- Average visibility in May: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





