Climate and monthly weather forecast
Charleston International Airport, SC

Charleston International Airport in South Carolina, USA, is located in an area identified by the Köppen climate classification system as Cfa, describing a humid subtropical zone with no dry season. The climate is characterized by warm humid summers and mild winters, with a high amount of rain falling throughout the year.

Throughout the year, Charleston International Airport experiences a substantial variation in weather conditions. The highest temperatures, averaging from 75°F (23.9°C) to 86°F (30°C), are reached between May and August, while the coldest months, where average temperatures drop to between 23°F (-5°C) and 45°F (7.2°C), occur from December to February. Rain is present throughout the year with slightly higher rainfall occurring from July to September, averaging 4" (102mm) to 4.8" (122mm). Monthly average numbers of days with rainfall ranges between 10 and 15 days.

Despite the lack of a dry season, a noticeable amount of sunlight still reaches the region. From May to August, Charleston International Airport enjoys a prolonged duration of daylight, from 13.9 hours to 14.3 hours, paired with abundant sunshine hours, ranging from 8 hours in May to 8 hours in August. The UV index during these months is considerably high, reaching values of 8 and 9. The shortest days and least amount of sunshine are found in December and January, with daylight duration going down to 10 hours and sunshine hours dropping to 3 to 4 hours per day.

Due to its subtropical climate, spring and autumn are ideal times to visit Charleston International Airport. In the months of April and May, temperatures provide gentle weather conditions, averaging between 57°F (13.9°C) and 75°F (23.9°C), paired with a moderate average rainfall of 3.4 to 3.8" (97mm). In comparison, autumn months of September and October offer similar conditions with temperatures between 79°F (26.1°C) and 68°F (20°C) and rainfall ranging from 2.8" (71mm) to 3.4" (86mm). These periods offer sufficient daylight and sunshine hours with relatively lower UV index values of 5 to 7, making outdoor activities pleasant and more enjoyable.

The summer months, specifically July and August, can provide a rather harsh environment due to high temperatures of 86°F (30°C) and 84°F (28.9°C) respectively. With high rainfall levels of 4.8" (122mm) and 4" (102mm) paired with a high UV index of 9, outdoor activities can become burdensome. On the other extreme, the winter months of December, January, and February, while not extremely cold with average temperatures mostly in the range from 23°F (-5°C) to 45°F (7.2°C), provide lesser daylight and sunshine hours of 10 to 11 hours and 3 to 4 hours respectively.

Spring blooms at Charleston International Airport manifest with warmed up temperature profiles varying between 57°F (13.9°C) and 75°F (23.9°C) from March to May. There is a moderate rainfall profile in these months, with averages spanning from 3.4" (86mm) to 3.8" (97mm) resulting in roughly 14 days of rainfall each month. This is complemented by extended daylight of 12 hours to 13.9 hours and sunshine hours extending from 6 to 8 hours.

Summer at Charleston International Airport gets notably hot and humid. Average temperatures run from 79°F (26.1°C) to 86°F (30°C) between June and August. Rainfall in these months varies from 3.4" (86mm) to a high of 4.8" (122mm) in July. Days have maximum daylight, extending from 14.1 hours to 14.3 hours and are filled with about 8 hours of sunshine. A high UV index of 9 commonly presents here.

Charleston International Airport experiences a gradual decrease in temperature from 79°F (26.1°C) to 57°F (13.9°C) during autumn months. Rainfall changes from high levels of 3.4" (86mm) and 4" (102mm) in September and August respectively to a relatively lower average of 2.8" (71mm) by October. Daylight hours in these months vary between 12.4 hours to 11.3 hours and there are about seven hours of daily sunshine.

Winter at Charleston International Airport is generally mild with average temperatures moving between 23°F (-5°C) to 46°F (7.8°C) during December, January, and February. Average monthly rainfall hovers around 3.1" (79mm) to 3.2" (81mm) and the region experiences around 14 days of rainfall each month. The daylight in these months reduces to 10 hours to 10.5 hours with sunshine hours dropping to a year-long minimum of 3 to 4 hours. The UV index is also at its lowest with a value of 2.

January's weather in Charleston International Airport sees a mix of rain and cold temperatures, contrasting with the milder climes experienced in later months. Temperature fluctuations are observed, reaching a high of 41°F (5°C) and plunging to a low of 23°F (-5°C). Weather in January »

With the arrival of February, Charleston experiences a slight change in weather patterns, though still remains in the grip of winter. This month is characterized by a subtle increase in temperature, cold nights, and consistent rainfall. Weather in February »

March signifies the departure of the severest winter temperatures at Charleston International Airport, with the weather beginning to warm. March's showers herald the approach of spring, with precipitation levels recorded at 3.8" (97mm). Weather in March »

With the onset of April, Charleston's weather begins to transform into warmer and milder conditions. Notably, the temperature elevates from chilly lows of 41°F (5°C) to a more comfortable range, hitting monthly highs of 66°F (18.9°C). Weather in April »

May truly brings spring weather to Charleston International Airport, with steadily increasing temperatures and a more pleasing climate. Being a rainy season, the precipitation averages around 3.8" (97mm), accompanied by cooler temperatures at night. Weather in May »

June ushers in the advent of summer at Charleston, bringing with it warm temperatures and relatively high humidity. The daily temperatures are expected to fluctuate significantly, hovering between highs of 82°F (27.8°C) and cooler lows that dip to 59°F (15°C) in the late hours. Weather in June »

July, in the heart of summer, boasts the highest temperatures of the year for Charleston International Airport. The mercury reaches a scorching 86°F (30°C) at the peak, making it the warmest month in the calendar. This month enjoys long daylight hours, sharing a striking balance with shorter nights. Weather in July »

With August comes a slight relief from the peak temperatures of July, yet maintaining the overall summer vibe in Charleston. The temperatures remain consistent, peaking at 84°F (28.9°C), and the days showcase amiable weather patterns. Weather in August »

September signifies a transition from the sweltering summer to the cooler autumn months in Charleston. The month is noted for a deceleration in temperature, standing at a comfortable high of 79°F (26.1°C). Rainfall continues its recess, whereas the UV index takes a setback, denoting the lessened sunlight hours. Weather in September »

By October, Charleston experiences more profound signs of autumn, with noticeably cooler weather and shorter days. The surmise of temperature fluctuation from 45°F (7.2°C) to 68°F (20°C) ascertains the advent of moderate cold breezes in the evening. Weather in October »

November fosters a typical autumn climate in Charleston, with decreasing temperatures and consistent rainfall. The mercury gauge measures temperatures down to the cooler end of the spectrum, hitting lows of 36°F (2.2°C). Shedding leaves mark the change in season, and the shorter daylight hours add a distinctive crispness to the air. Weather in November »

December witnesses the onset of winter at Charleston International Airport, replete with low temperatures and increased rainfall. The decline in temperature is noticeable, plunging to a chilly 27°F (-2.8°C) during cold nights. Weather in December »