Weather in Charleston, South Carolina
Roses open on the Piedmont edge. Day 59 of spring. Read this microseason across nine climate regions →
- TodayMay 16Foggy—81°58°
- SundayMay 17Overcast—85°68°
- MondayMay 18Overcast—82°66°
- TuesdayMay 19Clear—83°68°
- WednesdayMay 20Overcast—87°69°
- ThursdayMay 21Mostly Clear11%86°70°
- FridayMay 22Light Drizzle37%83°71°
- PM 2.5
- 13.3 μg/m³
- PM 10
- 18.9 μg/m³
- NO₂
- 6.7 μg/m³
- Ozone
- 87.0 μg/m³
- UV Index
- 0.0 Low
When the dew is on the grass, rain will never come to pass.
- Moonrise
- 10:33 AM
- Moonset
- 12:33 AM
- In sign
- ♊︎ Gemini
Roses open on the Piedmont edge
Charleston at a glance
- Today vs. normal: 10°F below the seasonal normal for this latitude
- Last frost: March 4 (climatological average for this latitude)
- Microseason: 28 of 72, May 16–20
- Planting window: Direct sow okra, melons, and southern peas. Thin carrot rows.
Right now in the garden
Peak growing season
As of May 17, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | lettuce, peas, spinach, radishes | — |
| April | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | — |
| May | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | — | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | — | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | fall brassicas, garlic (overwinter), carrots | — |
| December | — | — |
A year in weather
July brings Charleston's peak heat with mean temperatures around 82°F, while January delivers the year's coldest conditions at roughly 51°F. August sees the heaviest rainfall at 6.1 inches, contrasting with November's driest period of just 2.3 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 51° | 2.6″ | 5 |
| February | 53° | 2.6″ | 5 |
| March | 59° | 3.0″ | 5 |
| April | 66° | 3.0″ | 5 |
| May | 74° | 2.6″ | 4 |
| June | 79° | 4.8″ | 7 |
| July | 82° | 5.1″ | 8 |
| August | 81° | 6.1″ | 8 |
| September | 78° | 5.3″ | 6 |
| October | 69° | 4.1″ | 5 |
| November | 60° | 2.3″ | 4 |
| December | 54° | 2.9″ | 5 |
Regional context
Charleston belongs to the humid subtropical climate region, sharing temperature ranges, seasonal patterns, and growing conditions with other cities in this climate zone.
Similar climates: Columbia, SC, Greenville, SC, Myrtle Beach, SC, Rock Hill, SC, Spartanburg, SC.
Naturalist notes
Late May brings the arrival of ruby-throated hummingbirds returning from their winter grounds, their metallic calls echoing through Charleston's gardens.
Southern magnolia trees begin their spectacular bloom cycle in late May, releasing their lemony fragrance across the city's neighborhoods.
Frequently asked
- When does it freeze in Charleston?
- Mid-March typically marks Charleston's last spring frost, while the first fall frost usually occurs around mid-December.
- What is the rainy season in Charleston?
- August ranks as the wettest month, delivering about 6.1 inches of rain on average, contributing to the city's annual total of roughly 44 inches.
- What is the warmest month in Charleston?
- July typically records the year's highest temperatures, with averages around 82°F.
- What is the coldest month in Charleston?
- January brings the coldest temperatures, averaging about 51°F.
- When can I start a vegetable garden in Charleston?
- Cool-season crops like peas and lettuce can be planted around the last spring frost in mid-March, while warm-season crops such as tomatoes and peppers should wait 1–2 weeks after.
- How many rainy days does Charleston get?
- Charleston experiences about 65 rainy days per year on average.
- What hardiness zone is Charleston?
- Charleston's USDA hardiness zone depends on its lowest average winter temperature; the USDA's online lookup tool provides the current zone designation when you enter the city ZIP.
Climate
Charleston, South Carolina experiences a humid subtropical climate zone. Winter temperatures in January hover near 51°F, while summer brings July averages of 82°F — creating a 32°F seasonal swing.
Annual precipitation totals about 44 inches across roughly 65 rainy days throughout the year.
Geography determines Charleston's weather patterns through its latitude of 32.8°N, proximity to large water bodies, and elevation. These factors influence local plant growth, frost timing, and daily weather conditions.