May weather forecastJohns Island, SC
May
Weather in May
The last month of the spring, May, is also a moderately hot month in Johns Island, South Carolina, with an average temperature varying between 66.7°F (19.3°C) and 80.8°F (27.1°C).Temperature
The beginning of May marks a minor shift in the average high-temperature, moving from April's 74.1°F (23.4°C) to a still moderately hot 80.8°F (27.1°C). Nighttime temperatures in Johns Island consistently average a refreshing 66.7°F (19.3°C) during May.Heat index
The heat index value during May is appraised at 84.2°F (29°C). One might feel worn out with persistent exposure and activity, resulting in heat cramps.Evaluating the heat index requires understanding its values in the shade and with gentle winds. Exposure to the direct sun might augment heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is a composite of temperature and humidity figures to convey how warm it feels. Additional factors encompassing metabolic differences, the level of physical activity, and clothing can impact the individual's perception of temperature. By being directly under the sun, it's possible for the felt temperature to increase by 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Youngsters often neglect the necessity for rest and hydration. Thirst is a sign of advancing dehydration - thus the importance of maintaining hydration, specifically during long-lasting physical activities.
Humidity
In Johns Island, the average relative humidity in May is 75%.Rainfall
In Johns Island, during May, the rain falls for 13.4 days and regularly aggregates up to 1.42" (36mm) of precipitation. Throughout the year, there are 154.4 rainfall days, and 23.43" (595mm) of precipitation is accumulated.Snowfall
March through November are months without snowfall.Daylight
In May, the average length of the day in Johns Island is 13h and 51min.On the first day of the month, sunrise is at 6:32 am and sunset at 8:02 pm. On the last day of May, in Johns Island, sunrise is at 6:13 am and sunset at 8:22 pm EDT.
Sunshine
In May, the average sunshine in Johns Island is 10.4h.UV index
May through August, with an average maximum UV index of 7, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The UV index of 7 in May translates into these instructions:
Implement precautions and maintain sun safety methods. Avoidance of sunburn is demanded. Remember that UV radiation from the Sun is strongest between 10 a.m. and 4 p.m. Make an effort to limit direct sun exposure during this time. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Johns Island, 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
Johns Island, 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
Johns Island, 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
Johns Island, 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
Johns Island, 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
Johns Island, 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
Johns Island, 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
Johns Island, 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
Johns Island, 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
Johns Island, 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
Johns Island, 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
Johns Island, 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).
