Charleston
South Carolina, USA
Long-term weather forecast
Long-term weather forecast

May weather forecast and climate
Charleston, SC

Trees along both sides of a street in Charleston, South Carolina, in the twilight light
Trees along both sides of a street in Charleston, South Carolina, in the twilight light
Mayo, the last month of the spring, in Charleston, is another warm month, with temperature in the range of an average high of 83.1°F (28.4°C) and an average low of 61.9°F (16.6°C).

Temperature

In Mayo, the average high-temperature slightly increases, from 76.5°F (24.7°C) in Abril, to a still moderately hot 83.1°F (28.4°C). The average low-temperature, in Charleston, South Carolina, is 61.9°F (16.6°C).

Heat index

The average heat index in Mayo is estimated at a hot 89.4°F (31.9°C). Exhaustion is likely with prolonged exposure and activity. Sustaining activity may result in heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature', 'apparent temperature', 'feels like', or 'real feel', is a measure of how hot it feels when the actual air humidity is factored in. This effect is subjective, depending on the activity and individual's heat perception influenced by various reasons (wind, clothing, metabolic differences). Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.

Humidity

In Charleston, the average relative humidity is 72.5%.

Rainfall

In Charleston, in Mayo, during 7.8 rainfall days, 3.02" (76.7mm) of precipitation is typically accumulated. Throughout the year, there are 112.7 rainfall days, and 51.03" (1296.1mm) of precipitation is accumulated.

Snowfall

Enero, Marzo through Noviembre are months without snowfall in Charleston.

Ocean temperature

In Charleston, the average seawater temperature is 73°F (22.8°C).
Note: For individuals prone to feeling cold, swimming in 73.4°F (23°C) is still regarded as intolerable. A wetsuit is not a necessity, but sunshine, wind, and air temperature are essential factors for relishing swimming at 73°F (22.8°C).

Daylight

In Charleston, South Carolina, the average length of the day is 13.9h.

Sunshine

With an average of 9.5h of sunshine, Mayo has the most sunshine of the year in Charleston.

UV index

In Charleston, the average daily maximum UV index in Mayo is 9. A UV Index estimate of 8 to 10 represents a very high health risk from unsafe exposure to the UV radiation for average individuals.
Note: The daily maximum UV index of 9 interpret into the following advice:
Take extra precautions. Fair-skinned individuals may get burned in less than 10 minutes. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Prolonged stay under the direct sun should be avoided as much as possible, especially if a person burns easily. Sunscreen with a minimum 30 sun protection factor should always be used. Beware! The reflection of water and sand dramatically increases exposure to the UV rays.

What is the temperature in Mayo in Charleston?

In Charleston, in Mayo, the average high-temperature is 83.1°F (28.4°C), and the average low-temperature is 61.9°F (16.6°C). The average heat index (a.k.a. 'felt air temperature', 'real feel'), that combines air temperature and relative humidity, in Mayo is appraised at 89.4°F (31.9°C).

What is the average humidity in Mayo in Charleston?

The average relative humidity in Mayo is 72.5%.

How many days does it rain in Mayo in Charleston?

In Charleston, South Carolina, in Mayo, it is raining for 7.8 days, with typically 3.02" (76.7mm) of accumulated precipitation.

When it does not snow in Charleston?

Enero, Marzo through Noviembre are months without snowfall in Charleston.

What is the ocean temperature in Mayo in Charleston?

In Charleston, South Carolina, in Mayo, the average water temperature is 73°F (22.8°C). For individuals prone to feeling cold, swimming in 73.4°F (23°C) is still regarded as intolerable. A wetsuit is not a necessity, but sunshine, wind, and air temperature are essential factors for relishing swimming at 73°F (22.8°C).

How many hours of daylight does Charleston have in Mayo?

In Charleston, South Carolina, the average length of the day in Mayo is 13.9h.

What month has the most sunshine in Charleston?

Mayo has the most sunshine of the year in Charleston, with an average of 9.5h of sunshine.

How many hours of sunshine does Charleston have in Mayo?

In Mayo, the average sunshine in Charleston is 9.5h.

What is the UV index reading in Mayo in Charleston?

In Mayo, the average daily maximum UV index in Charleston is 9. A UV Index reading of 8 to 10 represents a very high health vulnerability from the exposure to the Sun's UV rays.
Average temperature in May - Charleston, SC
  • Average high temperature in May: 83.2°F

The warmest month (with the highest average high temperature) is July (91.1°F).
The month with the lowest average high temperature is January (59°F).

  • Average low temperature in May: 61.8°F

The month with the highest average low temperature is July (73°F).
The coldest month (with the lowest average low temperature) is January (37.5°F).

Average humidity in May - Charleston, SC
  • Average humidity in May: 72.5%

The month with the highest relative humidity is August (78.9%).
The month with the lowest relative humidity is February (67.4%).

Average rainfall in May - Charleston, SC
  • Average rainfall in May: 3"

The wettest month (with the highest rainfall) is August (7.2").
The driest month (with the lowest rainfall) is November (2.4").

Average rainfall days in May - Charleston, SC
  • Average rainfall days in May: 7.8 days

The month with the highest number of rainy days is August (13.2 days).
The month with the lowest number of rainy days is November (7 days).

Average snowfall in May - Charleston, SC
  • Average snowfall in May: 0"

The month with the highest snowfall is December (0.5").
Months with the lowest snowfall are January, March, April, May, June, July, August, September, October and November (0").

Average snowfall days in May - Charleston, SC
  • Average snowfall days in May: 0 days

Months with the highest number of snowfall days are February and December (0.2 days).
Months with the lowest number of snowfall days are March, April, May, June, July, August, September, October and November (0 days).

Average sea temperature in May - Charleston, SC
  • Average sea temperature in May: 73°F

The best month for swimming (with the highest average sea temperature) is August (83.5°F).
The coldest month (with the lowest average sea temperature) is February (61.9°F).

Average daylight in May / Average sunshine in May - Charleston, SC
  • Average daylight in May: 13.9h

The month with the longest days is June (Average daylight: 14.3h).
The month with shortest days is December (Average daylight: 10h).

  • Average sunshine in May: 9.5h

The month with most sunshine is May (Average sunshine: 9.5h).
The month with least sunshine is December (Average sunshine: 5.5h).

Average UV index in May - Charleston, SC
  • Average UV index in May: 9

Months with the highest UV index are June, July and August (UV index 10).
Months with the lowest UV index are January and December (UV index 3).