June weather forecast
Charleston, SC

June steers Charleston right into the heart of summer. The prominence of sunny days combined with optimal sea temperatures marks the start of the busy tourist season. Dealing with the heat becomes easier for locals and visitors alike, as they find respite in the cooling evening sea breezes. Of note, June stands out with the highest amount of rainfall, registering at 4.45" (113mm).

Temperature

As June begins, there's a slight increase in the average high-temperature, moving from a warm 79.5°F (26.4°C) in May to a still moderately hot 85.8°F (29.9°C). During June, Charleston's temperature falls to a steady low-temperature average of 74.7°F (23.7°C).

Heat index

Throughout June, the heat index is calculated to be a fiery hot 96.8°F (36°C). Take more caution, heat exhaustion and heat cramps may occur. Long-lasting activity may cause heatstroke.
One should consider that heat index numbers are for shaded settings and light wind. The heat index has the potential to rise by 15 Fahrenheit (8 Celsius) degrees with direct sunshine exposure.
Note: The heat index, also known as 'felt air temperature' or 'real feel', reflects the feeling of heat when considering both air temperature and humidity. The effect is personal, with varied weather perceptions among individuals due to differences in body mass, stature, and physical activity. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to children. Youngsters generally face more threats than adults given their lesser ability to sweat. Coupled with their larger skin surface relative to their small bodies and higher heat production due to their activities, they are more endangered.
The body's natural response to excessive warmth is perspiration, as it allows for cooling through sweat evaporation. With high air temperature and humidity (high heat index) conditions, sweat production is restricted, leading to an amplified perception of heat. As the body accumulates more heat than it can release, body temperature goes up, increasing the risk of heat-related health issues.

Humidity

In Charleston, the average relative humidity in June is 75%.

Rainfall

In June, in Charleston, the rain falls for 20.5 days. Throughout June, 4.45" (113mm) of precipitation is accumulated. In Charleston, during the entire year, the rain falls for 178.9 days and collects up to 41.93" (1065mm) of precipitation.

Snowfall

February through November are months without snowfall in Charleston.

Ocean temperature

In Charleston, the average seawater temperature in June is 79.3°F (26.3°C).
Note: In any water activity, temperatures between 77°F (25°C) and 84.2°F (29°C) are viewed as magnificent and exceptionally pleasant for prolonged enjoyment.

Daylight

The month with the longest days in Charleston is June, with an average of 14h and 18min of daylight.
On the first day of the month, sunrise is at 6:12 am and sunset at 8:23 pm. On the last day of June, sunrise is at 6:15 am and sunset at 8:31 pm EDT.

Sunshine

The average sunshine in June is 10.8h.

UV index

The months with the highest UV index are May through August, with an average maximum UV index of 7. A UV Index estimate of 6 to 7 represents a high threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The daily maximum UV index of 7 in June interprets into the following advice:
Use measures and accept sun safety conventions. Guarding against skin and eye trauma is of high priority. Avoid direct Sun exposure and seek shade from 10 a.m. to 4 p.m., the period of highest UV radiation. Remember, however, that not all shade structures offer full protection. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage. Take warning! Reflective sand and water surfaces intensify the Sun's UV rays.