Climate in Charleston (South Carolina)

The climate of Charleston, the main city of South Carolina, is subtropical, with mild winters (though characterized by short cold waves) and hot, humid summers, during which there are quite frequent thunderstorms.
The city is located in the southeastern United States, near the coast of the Atlantic Ocean, on a peninsula surrounded by the Ashley and Cooper rivers. On the coast there are islands and marshes.
The average temperature of the coldest month (January) is of 9.8 °C (49.6 °F), that of the warmest month (July) is of 28.1 °C (82.5 °F).
Precipitation amounts to 1,335 millimeters (52.5 inches) per year.



The winter, from December to February, is mild.
The sun often shines, although there are periods characterized by clouds, rain and wind.
Normally the days are mild, but at night it is often cold, and the temperature can approach the freezing point.
There may be warm periods even in the middle of winter, when the temperature can reach or exceed 25 °C (77 °F).
However, there may also be short cold spells, in which the temperature drops below freezing, usually down to -6/-7 °C (19/21 °F).
The record is -14.5 °C (6 °F), recorded in January 1985.
Snow in Charleston is very rare. Occasionally, a light snowfall can be observed, but it takes years to see the city in white. The snowfall of 23 December 1989 remains historic, when 15 centimeters (6 inches) fell and the snow lasted until Christmas. Other snowfalls occurred in February 2010, when 8.5 cm (3.3 in) fell, and in January 2018, when 13.5 cm (5.3 in) fell.

The summer, from June to September, is hot and muggy. Due to high humidity the heat is sweltering, even though the breeze blows from the sea. The combination of humidity and temperature can produce a perceived temperature of 40 °C (104 °F) and above.
On the hottest days of the year, the temperature usually reaches 37/38 °C (99/100 °F).
The sun often shines, but the sky is not always clear, as cloud coverings can form, which can give rise to thunderstorms.

Between late summer and early autumn, Charleston can be affected by hurricanes or tropical storms. Hurricane season runs from June to November, although the period in which they are most likely is from August to October. Hurricanes can cause extensive damage, especially along the coast. The city was hit particularly hard by Hurricane Ugo in September 1989.

Spring and autumn, from March to May and from early October to late November, are pleasantly warm seasons, with infrequent rains. Spring is the sunniest season.
Sometimes there can be some bursts of cold air, especially in March and November, which generally bring a bit of cold especially at night.
In April and October it can exceed 30 °C (86 °F), while in May there is already often summer-like heat.

The sea temperature ranges between 20 °C (68 °F) and 28.5 °C (83 °F). The sea is warm enough for swimming from May to November.

Best Time

To visit Charleston you can choose the period from mid-March to mid-April.
To go to the beach, in May the weather is generally good, with fewer thunderstorms than in summer, however, it can sometimes get a little cold at night.

Charleston - Climate data

In Charleston, the average temperature of the coldest month (January) is of 9.8 °C (49.6 °F), that of the warmest month (July) is of 28.1 °C (82.5 °F). Here are the average temperatures.
Precipitation amounts to 1335 millimeters (52.6 inches) per year: it is therefore quite abundant. It ranges from 70 mm (2.8 in) in the driest month (November) to 175 mm (6.9 in) in the wettest one (August). Here is the average precipitation.
The sea temperature ranges from 20 °C (68 °F) in March to
There are on average around 2810 sunshine hours per year. Here are the average hours of sunshine per day.

Charleston - Weather by month

Based on the period 1991-2020

---

January, the coldest month of the year, is generally a mild month. The average temperature is of 9.8 °C (50 °F), with a minimum of 3.8 °C (38.9 °F) and a maximum of 15.7 °C (60.2 °F).
On the coldest nights of the month, the temperature usually drops to around -5.5 °C (22 °F). However, it dropped to -10 °C (14 °F) in January 2018.
On the warmest days of the month, the temperature usually reaches around 25 °C (77 °F). However, it reached 27.2 °C (81 °F) in January 2005.
Precipitation amounts to 85 mm (3.3 in), distributed over 9 days.
The day lasts on average 10 hours and 20 minutes.
There are on average 6 hours of sunshine per day. So, the sun shines 56% of the time.
The average humidity is 68%.
The average wind speed is 13 kph (8 mph).
The average sea temperature is of 21 °C (69.5 °F). Therefore, the sea is cool for swimming.

---

February is generally a mild month. The average temperature is of 11.5 °C (53 °F), with a minimum of 5.3 °C (41.6 °F) and a maximum of 17.7 °C (63.8 °F).
On the coldest nights of the month, the temperature usually drops to around -3.5 °C (26 °F). However, it dropped to -8.9 °C (16 °F) in February 1996.
On the warmest days of the month, the temperature usually reaches around 26 °C (79 °F). However, it reached 30 °C (86 °F) in February 2018.
Precipitation amounts to 75 mm (3 in), distributed over 8 days.
The day lasts on average 11 hours and 0 minutes.
There are on average 6.5 hours of sunshine per day. So, the sun shines 61% of the time.
The average humidity is 67%.
The average wind speed is 14 kph (8 mph).
The average sea temperature is of 20.5 °C (68.5 °F). Therefore, the sea is cool for swimming.

---

March is generally a very mild month. The average temperature is of 14.8 °C (59 °F), with a minimum of 8.5 °C (47.3 °F) and a maximum of 21.2 °C (70.1 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around -0.5 °C (30.5 °F). However, it dropped to -6.2 °C (20.8 °F) in March 1996.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 29 °C (84 °F). However, it reached 32.2 °C (90 °F) in March 2017.
Precipitation amounts to 85 mm (3.3 in), distributed over 8 days.
The day lasts on average 12 hours and 0 minutes.
There are on average 8 hours of sunshine per day. So, the sun shines 66% of the time.
The average humidity is 65%.
The average wind speed is 14 kph (9 mph).
The average sea temperature is of 20 °C (68 °F). Therefore, the sea is very cool for swimming.

---

April is generally a warm month. The average temperature is of 18.8 °C (66 °F), with a minimum of 12.5 °C (54.5 °F) and a maximum of 25.1 °C (77.1 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 4 °C (39.5 °F). However, it dropped to -1.1 °C (30 °F) in April 2007.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 31 °C (88 °F). However, it reached 35 °C (95 °F) in April 2002.
Precipitation amounts to 85 mm (3.3 in), distributed over 8 days.
The day lasts on average 13 hours and 0 minutes.
There are on average 9 hours of sunshine per day. So, the sun shines 71% of the time.
The average humidity is 66%.
The average wind speed is 14 kph (9 mph).
The average sea temperature is of 21 °C (69.5 °F). Therefore, the sea is cool for swimming.

---

May is generally a warm to hot month. The average temperature is of 22.9 °C (73 °F), with a minimum of 17.2 °C (63 °F) and a maximum of 28.7 °C (83.6 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 10 °C (50 °F). However, it dropped to 6.1 °C (43 °F) in May 2018.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 34 °C (93 °F). However, it reached 38.3 °C (100.9 °F) in May 2019.
Precipitation amounts to 85 mm (3.3 in), distributed over 8 days.
The day lasts on average 13 hours and 55 minutes.
There are on average 9.5 hours of sunshine per day. So, the sun shines 68% of the time.
The average humidity is 70%.
The average wind speed is 13 kph (8 mph).
The average sea temperature is of 23.5 °C (74 °F). Therefore, the sea can be considered barely acceptable for swimming.

---

June is generally a warm to hot, muggy month. The average temperature is of 26.4 °C (79 °F), with a minimum of 21.3 °C (70.4 °F) and a maximum of 31.4 °C (88.5 °F).
On the coldest nights, the temperature usually drops to around 16.5 °C (61.5 °F). However, it dropped to 12 °C (53.6 °F) in June 1998.
On the warmest days, the temperature usually reaches around 36 °C (96.5 °F). However, it reached 38.9 °C (102 °F) in June 2011.
Precipitation amounts to 160 mm (6.3 in), distributed over 12 days.
The day lasts on average 14 hours and 20 minutes. So the days are long. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.
There are on average 9.5 hours of sunshine per day. So, the sun shines 65% of the time.
The average humidity is 75%. Hence, the air is normally humid.
The average wind speed is 12 kph (8 mph).
The average sea temperature is of 26.5 °C (79.5 °F). Therefore, the sea is pleasantly warm and allows long swims.

---

July, the hottest month of the year, is generally a very hot, muggy month. The average temperature is of 28.1 °C (82 °F), with a minimum of 23.2 °C (73.7 °F) and a maximum of 32.9 °C (91.3 °F).
On the coldest nights of the month, the temperature usually drops to around 20 °C (68 °F). However, it dropped to 16.1 °C (61 °F) in July 2010.
On the warmest days of the month, the temperature usually reaches around 36.5 °C (97.5 °F). However, it reached 38 °C (100.4 °F) in July 1999.
Precipitation amounts to 170 mm (6.7 in), distributed over 13 days.
The day lasts on average 14 hours and 0 minutes.
There are on average 9.5 hours of sunshine per day. So, the sun shines 66% of the time.
The average humidity is 76%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).
The average sea temperature is of 28 °C (82.5 °F). Therefore, the sea is pleasantly warm and allows long swims.

---

August is generally a warm to hot, muggy month. The average temperature is of 27.5 °C (81 °F), with a minimum of 22.8 °C (73.1 °F) and a maximum of 32.1 °C (89.8 °F).
On the coldest nights of the month, the temperature usually drops to around 19 °C (66.5 °F). However, it dropped to 15 °C (59 °F) in August 2004.
On the warmest days of the month, the temperature usually reaches around 36 °C (96.5 °F). However, it reached 39 °C (102.2 °F) in August 1999.
Precipitation amounts to 175 mm (6.9 in), distributed over 13 days.
The day lasts on average 13 hours and 20 minutes.
There are on average 8.5 hours of sunshine per day. So, the sun shines 62% of the time.
The average humidity is 78%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).
The average sea temperature is of 28.5 °C (83 °F). Therefore, the sea is pleasantly warm and allows long swims.

---

September is generally a warm to hot, muggy month. The average temperature is of 24.9 °C (77 °F), with a minimum of 20.2 °C (68.3 °F) and a maximum of 29.7 °C (85.4 °F).
On the coldest nights, the temperature usually drops to around 14 °C (57 °F). However, it dropped to 7.8 °C (46 °F) in September 1999.
On the warmest days, the temperature usually reaches around 34 °C (93 °F). However, it reached 36.7 °C (98.1 °F) in September 1999.
Precipitation amounts to 155 mm (6.1 in), distributed over 10 days.
The day lasts on average 12 hours and 20 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 59% of the time.
The average humidity is 77%. Hence, the air is normally humid.
The average wind speed is 12 kph (7 mph).
The average sea temperature is of 27.5 °C (82 °F). Therefore, the sea is pleasantly warm and allows long swims.

---

October is generally a warm month. The average temperature is of 19.9 °C (68 °F), with a minimum of 14.3 °C (57.7 °F) and a maximum of 25.5 °C (77.9 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 5.5 °C (42 °F). However, it dropped to 1.1 °C (34 °F) in October 2001.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 31 °C (87.5 °F). However, it reached 34.4 °C (93.9 °F) in October 2013.
Precipitation amounts to 110 mm (4.3 in), distributed over 7 days.
The day lasts on average 11 hours and 20 minutes.
There are on average 7 hours of sunshine per day. So, the sun shines 64% of the time.
The average humidity is 74%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).
The average sea temperature is of 25.5 °C (77.5 °F). Therefore, the sea is warm enough for swimming.

---

November is generally a very mild month. The average temperature is of 14.6 °C (58 °F), with a minimum of 8.4 °C (47.1 °F) and a maximum of 20.8 °C (69.4 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 0 °C (32 °F). However, it dropped to -5 °C (23 °F) in November 2014.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 28 °C (82.5 °F). However, it reached 30.6 °C (87.1 °F) in November 2003.
Precipitation amounts to 70 mm (2.8 in), distributed over 7 days.
The day lasts on average 10 hours and 30 minutes.
There are on average 6.5 hours of sunshine per day. So, the sun shines 60% of the time.
The average humidity is 72%. Hence, the air is normally humid.
The average wind speed is 12 kph (7 mph).
The average sea temperature is of 23 °C (73.5 °F). Therefore, the sea can be considered barely acceptable for swimming.

---

December is generally a mild month. The average temperature is of 11.2 °C (52 °F), with a minimum of 5.3 °C (41.6 °F) and a maximum of 17.1 °C (62.7 °F).
On the coldest nights of the month, the temperature usually drops to around -3.5 °C (26 °F). However, it dropped to -7.2 °C (19 °F) in December 2010.
On the warmest days of the month, the temperature usually reaches around 25 °C (77.5 °F). However, it reached 30 °C (86 °F) in December 2017.
Precipitation amounts to 85 mm (3.3 in), distributed over 9 days.
The day lasts on average 10 hours and 0 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
There are on average 5.5 hours of sunshine per day. So, the sun shines 55% of the time.
The average humidity is 71%. Hence, the air is normally humid.
The average wind speed is 12 kph (8 mph).
The average sea temperature is of 22 °C (71 °F). Therefore, the sea is cool for swimming.