Frost dates for Charleston, South Carolina
Charleston doesn't get a freezing night every winter: about 92 years in 100 have one. In those years, half have had their last frost by February 4 and half their first by December 30.
Frost dates for
Charleston, South Carolina
Last spring frost
February 4
Not every winter has one: about 92 years in 100 have a freezing night here. In those years, half have their last frost by this date, and 1 in 10 still have one after March 4.
First fall frost
December 30
In years with a freeze, half have their first one by this date, and 1 in 10 by December 2.
Growing season
321 days
Frost-free days in a typical year. 9 years in 10 get at least 289.
Hardiness zone
9a
2023 USDA map: the coldest night of winter averages 20°F to 25°F. On the 2012 map it was 8b, half a zone colder. All 4 ZIP codes within about 6 miles of the city's center are in zone 9a.
Stations near you disagree. NOAA's Charleston City (4 miles away, at 10 feet above sea level), the one we used, gives a typical last frost of February 4 and a typical first frost of December 30. NOAA's Charleston International Airport (6 miles away, at 40 feet above sea level) gives a typical last frost of March 7 and a typical first frost of November 27. So the typical last frost could fall anywhere from February 4 to March 7 and the typical first frost from November 27 to December 30, depending on whether your garden is more like one or the other. Local terrain matters: hillsides, valley floors, water and city heat can change frost dates a lot over a few miles. Treat the dates here as a starting point, and compare with a nearby gardener or your county extension office.
Print a year planner for Charleston
Frost risk through the year
How sure are these dates?
A frost date is a probability, not a promise. NOAA worked out, from 30 years of nightly lows, how often the last spring frost and the first fall frost fall on each date. The middle column is the typical year. The outer columns are the early and late years that come about once a decade.
| Early year 1 in 10 | Typical year 1 in 2 | Late year 1 in 10 | |
|---|---|---|---|
| Last frost in spring | January 5 | February 4 | March 4 |
| First frost in fall | December 2 | December 30 | January 25 |
The frost-free season between them runs 321 days in a typical year. In 1 year in 10 it is 357 days or longer, and in 1 year in 10 it is 289 days or shorter.
- Hard freeze (28°F): about 63 years in 100 have one. In those years the last typically comes on January 24 and the first on January 8. It is a harder freeze than the 32°F frost line, cold enough to damage many garden plants; how hardy a crop is decides whether it comes through. (The National Weather Service's own hard-freeze threshold varies from office to office.)
- Frost possible (36°F at the station): typically last on February 25 and first on December 10. On clear, still nights the ground can be several degrees colder than the thermometer, so frost can form on plants when the official reading is in the mid-30s.
Planting calendar for Charleston
These dates count from the typical last and first frosts, using the planting rules published by Colorado State University Extension (spring), Virginia Cooperative Extension (fall crops) and University of Minnesota Extension (garlic, where winters are hard). Weather in any one year can run early or late, so check the forecast before you plant tender crops.
Frost doesn't come every year here: about 92 years in 100 have at least one freezing night. The calendar is built on the dates for the years that do.
We don't give a garlic date here. The rule we use, from the University of Minnesota Extension, counts from the first killing frost, and it works where a hard freeze comes every year before the ground freezes. Your county's extension office can tell you when to plant garlic in your climate.
Your typical last frost comes before mid-February. Where winters are this mild, summer heat limits the garden as much as frost does, and most planting happens in fall and late winter. Your county's extension office publishes a calendar made for your climate.
| When | What to do | Why then |
|---|---|---|
| January | ||
| January 7 to 21 | Peas, spinach, lettuce, radishes, onion sets, turnips Sow outdoors, as early as | hardy crops: 2 to 4 weeks before the typical last frost |
| January 7 to 21 | Broccoli and cabbage Plant out, as early as | hardy crops: 2 to 4 weeks before the typical last frost |
| January 21 to February 4 | Beets, carrots, potatoes, Swiss chard Plant outdoors, as early as | semi-hardy crops: up to 2 weeks before the typical last frost |
| January 21 to February 4 | Cauliflower Plant out, as early as | semi-hardy: up to 2 weeks before the typical last frost |
| February | ||
| February 4 | Snap beans, sweet corn, cucumbers, summer squash Sow outdoors around | tender crops: around the typical last frost date |
| February 18 | Tomatoes, peppers, eggplant Plant out from | very tender: 2 weeks or more after the typical last frost |
| February 18 | Melons, winter squash, pumpkins, lima beans Sow outdoors from | very tender: 2 weeks or more after the typical last frost |
| August | ||
| August 4 to 18 | Cabbage for fall Start seeds | set the plants out by September 22 |
| August 24 to September 7 | Broccoli for fall Start seeds | set the plants out by October 12 |
| October | ||
| October 3 | Snap beans for fall Last date to sow | 60 days to harvest, plus 2 weeks for slower fall growth, plus 2 weeks because frost kills it |
| October 7 | Carrots for fall Last date to sow | 70 days to harvest, plus 2 weeks for slower fall growth |
| October 8 | Cucumbers for fall Last date to sow | 55 days to harvest, plus 2 weeks for slower fall growth, plus 2 weeks because frost kills it |
| October 12 | Peas for fall Last date to sow | 65 days to harvest, plus 2 weeks for slower fall growth |
| October 13 | Summer squash for fall Last date to sow | 50 days to harvest, plus 2 weeks for slower fall growth, plus 2 weeks because frost kills it |
| October 17 | Leaf lettuce and beets for fall Last date to sow | 60 days to harvest, plus 2 weeks for slower fall growth |
| October 27 | Turnips and kohlrabi for fall Last date to sow | 50 days to harvest, plus 2 weeks for slower fall growth |
| November | ||
| November 6 | Spinach for fall Last date to sow | 40 days to harvest, plus 2 weeks for slower fall growth |
| November 16 | Radishes for fall Last date to sow | 30 days to harvest, plus 2 weeks for slower fall growth |
| November 19 to December 17 | Broccoli and cabbage Start seeds indoors | 5 to 7 weeks before planting them out |
| December | ||
| December 2 | Tomatoes, peppers, squash, melons, cucumbers Watch the forecast from | in 1 fall in 10 the first frost comes by this date; pick tender crops before a frost |
| December 3 to 31 | Cauliflower Start seeds indoors | 5 to 7 weeks before planting out |
| December 17 to January 7 | Eggplant Start seeds indoors | 6 to 9 weeks before planting out |
| December 24 to January 7 | Peppers Start seeds indoors | 6 to 8 weeks before planting out |
| December 31 to January 14 | Tomatoes Start seeds indoors | 5 to 7 weeks before planting out |
Want more insurance? Shift every spring date 28 days later. That plans around March 4, the date after which only 1 spring in 10 has a frost.
For spring bulbs such as tulips and daffodils, plant once the soil has cooled to about 50 to 55°F and keep going until a couple of weeks before the ground freezes. Our guide to fall planting explains how to tell.
Where these numbers come from
These dates come from NOAA's weather station Charleston City (station USW00013782), 4 miles from the center of Charleston. It sits at about the same elevation, 10 feet above sea level. NOAA rates this station's record as standard: at least 24 of the 30 years, with gaps filled from nearby stations.
The same station also gives the frost dates for Mount Pleasant and James Island.
Our ZIP code lookup matches these 8 ZIP codes to the same station, so they get the same dates: 29401, 29403, 29407, 29409, 29412, 29424, 29425, 29455. Hardiness zones are worked out separately for each ZIP code.
Nearby places
- North Charleston, South Carolina: last frost around March 7, first frost around November 27 (8 miles away)
- Savannah, Georgia: last frost around March 2, first frost around November 30 (90 miles away)
- Columbia, South Carolina: last frost around March 13, first frost around November 19 (100 miles away)
See frost dates across South Carolina, or look up your own ZIP code for the station nearest you. Want the background? Read what a last frost date really means.