Barnwell, South Carolina climate: Normal weather by month, frost dates and records
Barnwell's normal year runs from 35°F January nights to 93°F July afternoons, with 48.7 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 18.2°C, January lows of 1°C, July highs of 34°C, 1,237 mm of precipitation a year.
- NOAA stationBarnwell (5 mi ENE)
- Station IDUSC00380490
- Location33.25°N 81.24°W
- Elevation245 ft (75 m)
- Population4,589
On October 23, the normal high in Barnwell is 76°F and the normal low 50°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Barnwell.
- Jan 59° 35°
- Feb 63° 37°
- Mar 70° 43°
- Apr 78° 50°
- May 85° 59°
- Jun 90° 67°
- Jul 93° 71°
- Aug 92° 70°
- Sep 87° 64°
- Oct 78° 53°
- Nov 69° 41°
- Dec 61° 37°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Barnwell each month?
July is the warmest month, with normal highs of 93°F; January the coldest, with normal lows of 35°F. The most precipitation falls in July (5.56 in), the least in November (2.76 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 59°F | 35°F | 46.8°F | 3.78 | – | <1 | 16 | 10 h 10 min |
| February | 63°F | 37°F | 50.2°F | 3.90 | – | <1 | 10 | 11 h |
| March | 70°F | 43°F | 56.4°F | 4.15 | – | <1 | 6 | 12 h |
| April | 78°F | 50°F | 64.1°F | 3.07 | – | 2 | <1 | 13 h |
| May | 85°F | 59°F | 72.4°F | 3.58 | – | 9 | <1 | 13 h 50 min |
| June | 90°F | 67°F | 78.8°F | 5.51 | – | 22 | <1 | 14 h 20 min |
| July | 93°F | 71°F | 81.9°F | 5.56 | – | 26 | <1 | 14 h 10 min |
| August | 92°F | 70°F | 80.8°F | 5.25 | – | 23 | <1 | 13 h 30 min |
| September | 87°F | 64°F | 75.4°F | 4.27 | – | 16 | <1 | 12 h 30 min |
| October | 78°F | 53°F | 65.7°F | 3.08 | – | 2 | <1 | 11 h 20 min |
| November | 69°F | 41°F | 55.1°F | 2.76 | – | <1 | 7 | 10 h 30 min |
| December | 61°F | 37°F | 49.2°F | 3.80 | – | <1 | 11 | 10 h |
| Year (annual) | 77°F | 52°F | 64.7°F | 48.71 | – | 100 | 50 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 15°C | 1°C | 8.2°C | 96 mm |
| February | 17°C | 3°C | 10.1°C | 99 mm |
| March | 21°C | 6°C | 13.6°C | 105 mm |
| April | 26°C | 10°C | 17.8°C | 78 mm |
| May | 30°C | 15°C | 22.4°C | 91 mm |
| June | 32°C | 20°C | 26.0°C | 140 mm |
| July | 34°C | 22°C | 27.7°C | 141 mm |
| August | 33°C | 21°C | 27.1°C | 133 mm |
| September | 31°C | 18°C | 24.1°C | 108 mm |
| October | 26°C | 12°C | 18.7°C | 78 mm |
| November | 20°C | 5°C | 12.8°C | 70 mm |
| December | 16°C | 3°C | 9.6°C | 97 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Bamberg (12 miles away), gets 0 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00380490; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Barnwell?
Normal highs sit between 65°F and 85°F in March, April, October and November.
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00380490.
When is the last frost in Barnwell?
In Barnwell, the last spring frost (32°F) comes after March 22 in half of years and after April 9 in one year in ten; the first autumn frost comes before November 9 in half of years and before October 30 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- March 221 year in 10 after April 9; 9 in 10 after March 1
- First autumn frost, half of years before
- November 91 year in 10 before October 30; 9 in 10 before November 25
NOAA puts the median frost-free season at 233 days, and the season without a hard freeze (28°F) at 258 days.
A hard freeze (28°F) comes after March 8 in half of springs and before November 20 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Barnwell in zone 8b in ZIP code 29812, the nearest ZIP area.
Frost dates for every NOAA station in South Carolina · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00380490; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Barnwell?
In a normal year in Barnwell, 100 days a year reach 90°F (8 of them 100°F or more) and 50 nights fall to 32°F or colder.
- Days at 90°F or more
- 100a normal year
- Days at 100°F or more
- 8a normal year
- Nights at 32°F or colder
- 50a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
Source: NOAA NCEI 1991-2020 annual normals, station USC00380490.
How sunny is Barnwell?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Barnwell, 4.6 kWh per square metre a day. July is the sunniest month (81%) and February the cloudiest (73%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 76% | 2.9 |
| February | 73% | 3.5 |
| March | 75% | 4.5 |
| April | 80% | 5.8 |
| May | 80% | 6.2 |
| June | 81% | 6.4 |
| July | 81% | 6.2 |
| August | 80% | 5.6 |
| September | 79% | 4.9 |
| October | 79% | 4.0 |
| November | 79% | 3.1 |
| December | 74% | 2.5 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Barnwell need?
A normal year in Barnwell brings 2,292 heating degree days, 57% fewer than the median U.S. place (5,373), and 2,221 cooling degree days, 2.4 times the median (908). Four months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 5,917 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 566 | 2 |
| February | 420 | 5 |
| March | 288 | 23 |
| April | 105 | 76 |
| May | 16 | 243 |
| June | 0 | 414 |
| July | 0 | 524 |
| August | 0 | 490 |
| September | 4 | 316 |
| October | 88 | 108 |
| November | 313 | 16 |
| December | 493 | 4 |
| Year (annual) | 2,292 | 2,221 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00380490. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Barnwell been warmer than normal lately?
2025 averaged 65.1°F, 0.4°F above the 1991-2020 normal of 64.7°F. 4 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 65.2°F | +0.5°F | 51.53 |
| 2023 | 65.9°F | +1.2°F | 52.02 |
| 2024 | 66.2°F | +1.5°F | 55.04 |
| 2025 | 65.1°F | +0.4°F | 43.28 |
Source: observed years: ACIS, station USC00380490. A year counts only with all twelve months complete.
How does Barnwell's climate compare?
Barnwell is warmer than 61 of the other 72 places with their own NOAA record in South Carolina, and wetter than 34. Across the 7,247 U.S. stations with normals, its annual mean of 64.7°F is warmer than 87%.
In the Köppen classification computed from these normals, Barnwell is Cfa: temperate, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Barnwell share this climate record?
3 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Hilda, SC421 people · 2 mi N
- Olar, SC206 people · 6 mi SE
- Govan, SC53 people · 4 mi SE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Barnwell's climate
What is the coldest month in Barnwell?
January, with a normal high of 59°F and a normal low of 35°F. The warmest is July (93°F by day, 71°F at night).
Does it snow in Barnwell?
Rarely. NOAA publishes no 1991-2020 snowfall normal for Barnwell's NOAA station; the nearest record that keeps one, Bamberg (12 miles away), records 0 inches of snow in a normal year.
What is the rainiest month in Barnwell?
July, with 5.56 in of precipitation in a normal year; the driest is November with 2.76 in.
What plant hardiness zone is Barnwell in?
The USDA's 2023 map puts Barnwell in zone 8b in ZIP code 29812, the nearest ZIP area.
How late can frost come in Barnwell?
In half of years the last 32°F night comes after March 22; in one year in ten it comes after April 9. Waiting until April 9 leaves about a one-in-ten chance of a later frost.
Nearby and next
- South Carolina climateThe statewide normals and every place in the state
- Blackville, SC9 miles from this station, 63.9°F a year
- Bamberg, SC12 miles from this station, 64.4°F a year
- Allendale, SC17 miles from this station, 63.4°F a year
- Orangeburg, SC26 miles from this station, 65.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made