, 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.
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).
amounts to 1,335 millimeters (52.5 inches) per year.
, 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).
, in which the temperature drops below freezing, usually down to -6/-7 °C (19/21 °F).
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.
, 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.
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.
, 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.
temperature ranges between 20 °C (68 °F) and 28.5 °C (83 °F). The sea is warm enough for swimming from May to November.
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.
. Here are the average temperatures.
January, the coldest month of the year, is generally a mild month. The average temperature is of
9.8 °C, with a minimum of
3.8 °C and a maximum of
15.7 °C.

On the coldest nights of the month, the temperature usually drops to around
-5.5 °C. However, it dropped to
-10 °C in January 2018.

On the warmest days of the month, the temperature usually reaches around
25 °C. However, it reached
27.2 °C in January 2005.

Precipitation amounts to
85 mm, 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 of
13.1 kph.

The average sea temperature is of
20.8 °C. Therefore, the sea is cool for swimming.
February is generally a mild month. The average temperature is of
11.5 °C, with a minimum of
5.3 °C and a maximum of
17.7 °C.

On the coldest nights of the month, the temperature usually drops to around
-3.5 °C. However, it dropped to
-8.9 °C in February 1996.

On the warmest days of the month, the temperature usually reaches around
26 °C. However, it reached
30 °C in February 2018.

Precipitation amounts to
75 mm, 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 of
13.5 kph.

The average sea temperature is of
20.3 °C. Therefore, the sea is cool for swimming.
March is generally a very mild month. The average temperature is of
14.8 °C, with a minimum of
8.5 °C and a maximum of
21.2 °C.

On the coldest nights of the month, the temperature usually drops to around
-0.5 °C. However, it dropped to
-6.2 °C in March 1996.

On the warmest days of the month, the temperature usually reaches around
29 °C. However, it reached
32.2 °C in March 2017.

Precipitation amounts to
85 mm, 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 of
14.5 kph.

The average sea temperature is of
20.1 °C. Therefore, the sea is very cool for swimming.
April is generally a warm month. The average temperature is of
18.8 °C, with a minimum of
12.5 °C and a maximum of
25.1 °C.

On the coldest nights of the month, the temperature usually drops to around
4 °C. However, it dropped to
-1.1 °C in April 2007.

On the warmest days of the month, the temperature usually reaches around
31 °C. However, it reached
35 °C in April 2002.

Precipitation amounts to
85 mm, 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 of
14.5 kph.

The average sea temperature is of
20.8 °C. Therefore, the sea is cool for swimming.
May is generally a warm to hot month. The average temperature is of
22.9 °C, with a minimum of
17.2 °C and a maximum of
28.7 °C.

On the coldest nights of the month, the temperature usually drops to around
10 °C. However, it dropped to
6.1 °C in May 2018.

On the warmest days of the month, the temperature usually reaches around
34 °C. However, it reached
38.3 °C in May 2019.

Precipitation amounts to
85 mm, 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 of
13.3 kph.

The average sea temperature is of
23.4 °C. 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, with a minimum of
21.3 °C and a maximum of
31.4 °C.

On the coldest nights of the month, the temperature usually drops to around
16.5 °C. However, it dropped to
12 °C in June 1998.

On the warmest days of the month, the temperature usually reaches around
36 °C. However, it reached
38.9 °C in June 2011.

Precipitation amounts to
160 mm, 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 of
12.2 kph.

The average sea temperature is of
26.4 °C. 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, with a minimum of
23.2 °C and a maximum of
32.9 °C.

On the coldest nights of the month, the temperature usually drops to around
20 °C. However, it dropped to
16.1 °C in July 2010.

On the warmest days of the month, the temperature usually reaches around
36.5 °C. However, it reached
38 °C in July 1999.

Precipitation amounts to
170 mm, 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 of
11.4 kph.

The average sea temperature is of
28.1 °C. 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, with a minimum of
22.8 °C and a maximum of
32.1 °C.

On the coldest nights of the month, the temperature usually drops to around
19 °C. However, it dropped to
15 °C in August 2004.

On the warmest days of the month, the temperature usually reaches around
36 °C. However, it reached
39 °C in August 1999.

Precipitation amounts to
175 mm, 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 of
10.8 kph.

The average sea temperature is of
28.4 °C. 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, with a minimum of
20.2 °C and a maximum of
29.7 °C.

On the coldest nights of the month, the temperature usually drops to around
14 °C. However, it dropped to
7.8 °C in September 1999.

On the warmest days of the month, the temperature usually reaches around
34 °C. However, it reached
36.7 °C in September 1999.

Precipitation amounts to
155 mm, 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 of
11.7 kph.

The average sea temperature is of
27.7 °C. Therefore, the sea is pleasantly warm and allows long swims.
October is generally a warm month. The average temperature is of
19.9 °C, with a minimum of
14.3 °C and a maximum of
25.5 °C.

On the coldest nights of the month, the temperature usually drops to around
5.5 °C. However, it dropped to
1.1 °C in October 2001.

On the warmest days of the month, the temperature usually reaches around
31 °C. However, it reached
34.4 °C in October 2013.

Precipitation amounts to
110 mm, 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 of
11.4 kph.

The average sea temperature is of
25.4 °C. Therefore, the sea is warm enough for swimming.
November is generally a very mild month. The average temperature is of
14.6 °C, with a minimum of
8.4 °C and a maximum of
20.8 °C.

On the coldest nights of the month, the temperature usually drops to around
0 °C. However, it dropped to
-5 °C in November 2014.

On the warmest days of the month, the temperature usually reaches around
28 °C. However, it reached
30.6 °C in November 2003.

Precipitation amounts to
70 mm, 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 of
11.6 kph.

The average sea temperature is of
23 °C. Therefore, the sea can be considered barely acceptable for swimming.
December is generally a mild month. The average temperature is of
11.2 °C, with a minimum of
5.3 °C and a maximum of
17.1 °C.

On the coldest nights of the month, the temperature usually drops to around
-3.5 °C. However, it dropped to
-7.2 °C in December 2010.

On the warmest days of the month, the temperature usually reaches around
25 °C. However, it reached
30 °C in December 2017.

Precipitation amounts to
85 mm, 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 of
12.1 kph.

The average sea temperature is of
21.8 °C. Therefore, the sea is cool for swimming.