Ninety Nine Island, South Carolina climate: Climate normals at a NOAA weather station
Ninety Nine Island's normal year runs from 27°F January nights to 88°F July afternoons, with 45.3 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 14.4°C, January lows of −3°C, July highs of 31°C, 1,151 mm of precipitation a year.
- NOAA stationNinety Nine Island
- Station IDUSC00386293
- Location35.03°N 81.49°W
- Elevation500 ft (152 m)
On October 23, the normal high in Ninety Nine Island is 70°F and the normal low 42°F, and the chance of measurable rain or snow is 23%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Ninety Nine Island.
- Jan 51° 27°
- Feb 55° 29°
- Mar 63° 35°
- Apr 72° 43°
- May 78° 53°
- Jun 84° 62°
- Jul 88° 66°
- Aug 86° 65°
- Sep 81° 58°
- Oct 72° 46°
- Nov 62° 34°
- Dec 54° 29°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Ninety Nine Island each month?
July is the warmest month, with normal highs of 88°F; January the coldest, with normal lows of 27°F. The most precipitation falls in August (4.68 in), the least in October (3.06 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 51°F | 27°F | 38.7°F | 3.70 | 9 | <1 | 21 | 10 h |
| February | 55°F | 29°F | 42.1°F | 3.31 | 9 | <1 | 18 | 10 h 50 min |
| March | 63°F | 35°F | 48.8°F | 4.39 | 10 | <1 | 13 | 11 h 50 min |
| April | 72°F | 43°F | 57.1°F | 3.65 | 9 | <1 | 4 | 13 h |
| May | 78°F | 53°F | 65.3°F | 3.63 | 9 | 1 | <1 | 14 h |
| June | 84°F | 62°F | 72.9°F | 4.11 | 10 | 7 | <1 | 14 h 30 min |
| July | 88°F | 66°F | 76.7°F | 3.72 | 10 | 13 | <1 | 14 h 20 min |
| August | 86°F | 65°F | 75.6°F | 4.68 | 9 | 10 | <1 | 13 h 30 min |
| September | 81°F | 58°F | 69.6°F | 3.63 | 7 | 4 | <1 | 12 h 30 min |
| October | 72°F | 46°F | 58.7°F | 3.06 | 7 | <1 | 3 | 11 h 20 min |
| November | 62°F | 34°F | 47.9°F | 3.42 | 8 | <1 | 15 | 10 h 20 min |
| December | 54°F | 29°F | 41.3°F | 4.02 | 10 | <1 | 20 | 9 h 50 min |
| Year (annual) | 70°F | 46°F | 57.9°F | 45.32 | 104 | 34 | 93 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 11°C | −3°C | 3.7°C | 94 mm |
| February | 13°C | −2°C | 5.6°C | 84 mm |
| March | 17°C | 2°C | 9.3°C | 112 mm |
| April | 22°C | 6°C | 13.9°C | 93 mm |
| May | 26°C | 12°C | 18.5°C | 92 mm |
| June | 29°C | 16°C | 22.7°C | 104 mm |
| July | 31°C | 19°C | 24.8°C | 94 mm |
| August | 30°C | 18°C | 24.2°C | 119 mm |
| September | 27°C | 15°C | 20.9°C | 92 mm |
| October | 22°C | 8°C | 14.8°C | 78 mm |
| November | 16°C | 1°C | 8.8°C | 87 mm |
| December | 12°C | −2°C | 5.2°C | 102 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Shelby (20 miles away), gets 4 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00386293; 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.
Which months are mildest at Ninety Nine Island?
Normal highs sit between 65°F and 85°F in April, May, June, September and October. Of those, October has the fewest days with rain (7).
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 USC00386293.
When is the last frost at Ninety Nine Island?
In Ninety Nine Island, the last spring frost (32°F) comes after April 20 in half of years and after May 6 in one year in ten; the first autumn frost comes before October 24 in half of years and before October 11 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
- April 201 year in 10 after May 6; 9 in 10 after April 2
- First autumn frost, half of years before
- October 241 year in 10 before October 11; 9 in 10 before November 5
NOAA puts the median frost-free season at 186 days, and the season without a hard freeze (28°F) at 210 days.
A hard freeze (28°F) comes after April 6 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Ninety Nine Island in zone 8a in ZIP code 29743, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 7b: the coldest night of a typical year reaches 8°F (28 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in South Carolina · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00386293; 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.
How hot and how cold does it get at Ninety Nine Island?
In a normal year in Ninety Nine Island, 34 days a year reach 90°F, 93 nights fall to 32°F or colder and 104 days bring measurable precipitation.
- Days at 90°F or more
- 34a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 93a normal year
- Days that stay below freezing
- 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 104a normal year
The highest temperature in this station's record (since 1960) is 106°F, on August 21, 1983; the lowest is −4°F, on January 21, 1985.
The wettest calendar year on that record is 1975, with 62.79 in; the snowiest season is 1971–72, with 15.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00386293; records: ACIS (NOAA Regional Climate Centers), station USC00386293. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Ninety Nine Island?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds at Ninety Nine Island, 4.4 kWh per square metre a day. June is the sunniest month (80%) and February the cloudiest (72%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 75% | 2.6 |
| February | 72% | 3.3 |
| March | 73% | 4.3 |
| April | 76% | 5.5 |
| May | 76% | 6.0 |
| June | 80% | 6.3 |
| July | 78% | 6.0 |
| August | 79% | 5.5 |
| September | 77% | 4.7 |
| October | 77% | 3.8 |
| November | 78% | 3.0 |
| December | 72% | 2.3 |
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 many heating and cooling degree days does Ninety Nine Island record?
A normal year at Ninety Nine Island brings 3,789 heating degree days, 29% fewer than the median U.S. place (5,373), and 1,235 cooling degree days, 36% 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 4,124 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 815 | 0 |
| February | 641 | 0 |
| March | 505 | 1 |
| April | 250 | 15 |
| May | 75 | 86 |
| June | 6 | 244 |
| July | 0 | 364 |
| August | 0 | 331 |
| September | 27 | 165 |
| October | 221 | 27 |
| November | 514 | 1 |
| December | 733 | 0 |
| Year (annual) | 3,789 | 1,235 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00386293. 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.
Have recent years at Ninety Nine Island been warmer than normal?
Over 47 complete years from 1961 to 2019, the station's annual mean temperature rose at a fitted 3.6°F per century (+0.20°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Ninety Nine Island's climate compare?
Ninety Nine Island is warmer than 1 of the 73 places with their own NOAA record in South Carolina, and wetter than 11. Across the 7,247 U.S. stations with normals, its annual mean of 57.9°F is warmer than 69%.
In the Köppen classification computed from these normals, Ninety Nine Island 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 Ninety Nine Island share this climate record?
7 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.
- Kings Mountain, NC11,797 people · 16 mi NE
- Grover, NC811 people · 10 mi N
- Patterson Springs, NC581 people · 14 mi N
- Hickory Grove, SC469 people · 6 mi SE
- Earl, NC208 people · 12 mi N
- Smyrna, SC55 people · 5 mi E
- Cherokee Falls, SC28 people · 4 mi NW
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 Ninety Nine Island's climate
What is the coldest month at Ninety Nine Island?
January, with a normal high of 51°F and a normal low of 27°F. The warmest is July (88°F by day, 66°F at night).
Does it snow at Ninety Nine Island?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Shelby (20 miles away), records 4 inches of snow in a normal year.
What is the rainiest month at Ninety Nine Island?
August, with 4.68 in of precipitation in a normal year; the driest is October with 3.06 in.
What plant hardiness zone is Ninety Nine Island in?
The USDA's 2023 map puts Ninety Nine Island in zone 8a in ZIP code 29743, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches 8°F (28 years, 1991-2020): zone 7b.
How late can frost come at Ninety Nine Island?
In half of years the last 32°F night comes after April 20; in one year in ten it comes after May 6. Waiting until May 6 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
- York, SC19 miles from this station, 59.7°F a year
- Shelby, NC20 miles from this station, 59.2°F a year
- Gastonia, NC22 miles from this station, 62.1°F a year
- Rock Hill, SC25 miles from this station, 61.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made