Sumter, South Carolina climate: Normal weather by month, frost dates and records
Sumter's normal year runs from 33°F January nights to 90°F July afternoons, with 48.8 inches of precipitation and less than an inch of snow (0.3 in) a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 16.7°C, January lows of 0°C, July highs of 32°C, 1,240 mm of precipitation a year.
- NOAA stationSumter
- Station IDUSC00388440
- Location33.94°N 80.36°W
- Elevation177 ft (54 m)
- Population42,958
On October 23, the normal high in Sumter is 72°F and the normal low 48°F, and the chance of measurable rain or snow is 25%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Sumter.
- Jan 55° 33°
- Feb 59° 35°
- Mar 66° 41°
- Apr 75° 50°
- May 81° 58°
- Jun 87° 66°
- Jul 90° 70°
- Aug 89° 68°
- Sep 83° 63°
- Oct 74° 51°
- Nov 65° 40°
- Dec 57° 35°
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 Sumter each month?
July is the warmest month, with normal highs of 90°F; January the coldest, with normal lows of 33°F. The most precipitation falls in July (5.75 in), the least in November (2.94 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 55°F | 33°F | 43.9°F | 3.78 | 11 | <1 | 16 | 10 h 10 min |
| February | 59°F | 35°F | 46.7°F | 3.47 | 10 | <1 | 12 | 11 h |
| March | 66°F | 41°F | 53.6°F | 3.67 | 9 | <1 | 7 | 11 h 50 min |
| April | 75°F | 50°F | 62.2°F | 3.40 | 8 | 1 | <1 | 13 h |
| May | 81°F | 58°F | 69.5°F | 3.78 | 9 | 4 | <1 | 13 h 50 min |
| June | 87°F | 66°F | 76.6°F | 5.05 | 12 | 13 | <1 | 14 h 20 min |
| July | 90°F | 70°F | 79.9°F | 5.75 | 11 | 20 | <1 | 14 h 10 min |
| August | 89°F | 68°F | 78.5°F | 4.92 | 11 | 14 | <1 | 13 h 30 min |
| September | 83°F | 63°F | 73.2°F | 4.36 | 9 | 6 | <1 | 12 h 30 min |
| October | 74°F | 51°F | 62.6°F | 3.88 | 8 | <1 | <1 | 11 h 20 min |
| November | 65°F | 40°F | 52.4°F | 2.94 | 8 | <1 | 7 | 10 h 30 min |
| December | 57°F | 35°F | 46.2°F | 3.83 | 11 | <1 | 14 | 9 h 50 min |
| Year (annual) | 74°F | 51°F | 62.1°F | 48.83 | 117 | 58 | 56 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 13°C | 0°C | 6.6°C | 96 mm |
| February | 15°C | 2°C | 8.2°C | 88 mm |
| March | 19°C | 5°C | 12.0°C | 93 mm |
| April | 24°C | 10°C | 16.8°C | 86 mm |
| May | 27°C | 14°C | 20.8°C | 96 mm |
| June | 31°C | 19°C | 24.8°C | 128 mm |
| July | 32°C | 21°C | 26.6°C | 146 mm |
| August | 31°C | 20°C | 25.8°C | 125 mm |
| September | 29°C | 17°C | 22.9°C | 111 mm |
| October | 24°C | 11°C | 17.0°C | 99 mm |
| November | 18°C | 4°C | 11.3°C | 75 mm |
| December | 14°C | 2°C | 7.9°C | 97 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00388440; 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 Sumter?
Normal highs sit between 65°F and 85°F in March, April, May, September and October. Of those, October has the fewest days with rain (8).
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 USC00388440.
When is the last frost in Sumter?
In Sumter, the last spring frost (32°F) comes after March 24 in half of years and after April 7 in one year in ten; the first autumn frost comes before November 7 in half of years and before October 28 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 241 year in 10 after April 7; 9 in 10 after March 5
- First autumn frost, half of years before
- November 71 year in 10 before October 28; 9 in 10 before November 26
NOAA puts the median frost-free season at 230 days, and the season without a hard freeze (28°F) at 257 days.
A hard freeze (28°F) comes after March 13 in half of springs and before November 21 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Sumter in zone 8b across its 2 ZIP code areas (8b in 29150, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Sumter's NOAA station is in zone 8b: the coldest night of a typical year reaches 16°F (26 complete years).
Frost dates for every NOAA station in South Carolina · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00388440; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
What hardiness zone is each Sumter ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Sumter's 2 ZIP code areas are all in zone 8b. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Sumter?
In a normal year in Sumter, 58 days a year reach 90°F (1 of them 100°F or more), 56 nights fall to 32°F or colder and 117 days bring measurable precipitation.
- Days at 90°F or more
- 58a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 56a normal year
- Days that stay below freezing
- 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 117a normal year
The highest temperature in this station's record (since 1901) is 105°F, on July 7, 1904; the lowest is 2°F, on January 21, 1985.
The wettest calendar year on that record is 1959, with 70.69 in; the snowiest season is 1959–60, with 11.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00388440; records: ACIS (NOAA Regional Climate Centers), station USC00388440. Records use complete months only; a month missing more than three days is left out.
How sunny is Sumter?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Sumter, 4.6 kWh per square metre a day. July is the sunniest month (82%) 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 | 81% | 5.8 |
| May | 80% | 6.2 |
| June | 82% | 6.4 |
| July | 82% | 6.2 |
| August | 80% | 5.6 |
| September | 79% | 4.8 |
| October | 80% | 4.0 |
| November | 79% | 3.1 |
| December | 76% | 2.6 |
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 Sumter need?
A normal year in Sumter brings 2,821 heating degree days, 47% fewer than the median U.S. place (5,373), and 1,796 cooling degree days, 98% more than the median (908). Five months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 5,189 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 653 | 1 |
| February | 512 | 1 |
| March | 365 | 11 |
| April | 141 | 56 |
| May | 33 | 172 |
| June | 2 | 349 |
| July | 0 | 462 |
| August | 0 | 417 |
| September | 10 | 255 |
| October | 134 | 61 |
| November | 386 | 8 |
| December | 585 | 3 |
| Year (annual) | 2,821 | 1,796 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00388440. 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 Sumter been warmer than normal lately?
2025 averaged 64.6°F, 2.5°F above the 1991-2020 normal of 62.1°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 62.7°F | +0.6°F | 42.34 |
| 2022 | 64.3°F | +2.2°F | 43.24 |
| 2023 | 65.2°F | +3.1°F | 54.69 |
| 2024 | 65.8°F | +3.7°F | 36.88 |
| 2025 | 64.6°F | +2.5°F | – |
Over 67 complete years from 1930 to 2025, the station's annual mean temperature rose at a fitted -0.5°F per century (−0.03°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00388440; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Sumter's climate compare?
Sumter is warmer than 25 of the other 72 places with their own NOAA record in South Carolina, and wetter than 36. Across the 7,247 U.S. stations with normals, its annual mean of 62.1°F is warmer than 80%.
In the Köppen classification computed from these normals, Sumter 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 Sumter share this climate record?
8 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.
- Lakewood, SC3,154 people · 7 mi S
- Dalzell, SC2,949 people · 7 mi NW
- Privateer, SC2,294 people · 9 mi S
- South Sumter, SC1,808 people · 4 mi S
- East Sumter, SC852 people · 4 mi E
- Mayesville, SC550 people · 9 mi E
- Mulberry, SC230 people · 2 mi NE
- Oswego, SC211 people · 6 mi NE
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 Sumter's climate
What is the coldest month in Sumter?
January, with a normal high of 55°F and a normal low of 33°F. The warmest is July (90°F by day, 70°F at night).
Does it snow in Sumter?
Rarely: NOAA's normal is 0.3 inch a year.
What is the rainiest month in Sumter?
July, with 5.75 in of precipitation in a normal year; the driest is November with 2.94 in.
What plant hardiness zone is Sumter in?
The USDA's 2023 map puts Sumter in zone 8b across its 2 ZIP code areas (8b in 29150, the largest). By the same method at Sumter's NOAA station, the coldest night of a typical year reaches 16°F (26 years, 1991-2020): zone 8b.
How late can frost come in Sumter?
In half of years the last 32°F night comes after March 24; in one year in ten it comes after April 7. Waiting until April 7 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Sumter in OctoberThis month day by day, its records and recent years
- South Carolina climateThe statewide normals and every place in the state
- Wedgefield, SC10 miles from this station, 64.2°F a year
- Elliott, SC17 miles from this station, 63.0°F a year
- Manning, SC19 miles from this station, 63.1°F a year
- Bishopville, SC21 miles from this station, 62.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made