Ninety Nine Island, SC Climate: Temperature & Rain by Month
Explore NOAA NCEI's 1991–2020 climate normals → and a clearly labeled PlainClimate comfort calculation
30-year climate normals (1991-2020) from Ninety Nine Island's primary NOAA station, NINETY NINE IS.
The climate verdict for Ninety Nine Island
Water is the standout signal in Ninety Nine Island, South Carolina: 45.3 inches of precipitation in a normal year. Against that wet profile, NOAA records an annual average of 58°F. It scores 80/100 for climate comfort (excellent), putting it in the top third of station-mapped location scores and exceeding 76% of them.
- 58°F
- average temperature, NOAA 1991-2020 normal
- 80/100
- comfort score, above 76% of station-mapped location scores
- 45.3"
- annual precipitation
- 187 days
- frost-free days per growing season
Ninety Nine Island: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00386293 · Ninety Nine Island, SC 58°F mean · 45.3" precip
TEMP-MILD · RANK-UPPER · PHOTO-FINISH · PRCP-MID · SWING-MID · COMF-TOP · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-MILD 58°F
- RANK-UPPER #4,734
- PHOTO-FINISH ≈ Morganton
- PRCP-MID 45.3"
- SWING-MID 38°F
- COMF-TOP 80/100
- LOAD-HEAT 3,789 HDD
- STN-1 USC00386293
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Morganton, NC (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every SC station list.
- Ninety Nine Isl… (this station) 58°F
- Hot Hot Springs, NC 58°F
- Near Morganton, NC 58°F
- Near Marion, NC 58°F
- Near Soddy Daisy-mow…, TN 58°F
Climate Living Index · Ninety Nine Island
Ninety Nine Island: 68/100 · grade C
Ninety Nine Island publishes 4 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 2 missing weights rescale to 100.
PlainClimate-derived for Ninety Nine Island, not an official NOAA rating. Rankings still use Comfort Score 80/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 99 calendar days | 76/100 · B |
| Annual temperature balance | 57.9°F · 9.6° from 67.5°F | 69/100 · C |
| Precipitation balance | 45.3 in · 10.3 from 35 in | 64/100 · C |
| Frost-free season | 187 days/year | 55/100 · C |
Ninety Nine Island · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Ninety Nine Island is a temperate Köppen climate: Cfa
Coldest-month mean 38.7°F and warmest-month mean 76.7°F place this station in temperate, no dry season, hot summer climates (Cfa). Class Cfa is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: temperate, specifically temperate, no dry season, hot summer.
- Köppen code
- Cfa
- Group
- Temperate
- Warmest month
- 76.7°F
- Coldest month
- 38.7°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Ninety Nine Island sits across the climate record
Three NOAA fields for Ninety Nine Island's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 69th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- 69th percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- Narrower than 73%
- Warmest-to-coldest month gap for Ninety Nine Island is compact versus 6,861 complete station-years.
How Ninety Nine Island compares across U.S. station-mapped locations
Ninety Nine Island's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
80 Top 24% score exceeds 76% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). Below this entry.
- 50–60: 1,329 station-mapped locations (21%). Below this entry.
- 60–70: 1,236 station-mapped locations (20%). Below this entry.
- 70–80: 650 station-mapped locations (11%). Below this entry.
- 80–90: 921 station-mapped locations (15%). This entry sits in this band.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Ninety Nine Island's measured station temperature trend
MethodologyAcross 47 complete annual observations from 1961 to 2019, NINETY NINE IS warmed at a fitted rate of 0.20°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Ninety Nine Island primary station fitted change +0.20 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|
| January | 51°F (11°C) | 27°F (-3°C) | 39°F (4°C) | 3.7" | 21.3 | 0.0 |
| February | 55°F (13°C) | 29°F (-2°C) | 42°F (6°C) | 3.3" | 17.9 | 0.0 |
| March | 63°F (17°C) | 35°F (2°C) | 49°F (9°C) | 4.4" | 12.6 | 0.0 |
| April | 72°F (22°C) | 43°F (6°C) | 57°F (14°C) | 3.6" | 3.5 | 0.0 |
| May | 78°F (26°C) | 53°F (12°C) | 65°F (19°C) | 3.6" | 0.2 | 0.8 |
| June | 84°F (29°C) | 62°F (16°C) | 73°F (23°C) | 4.1" | 0.0 | 6.5 |
| July | 88°F (31°C) | 66°F (19°C) | 77°F (25°C) | 3.7" | 0.0 | 13.2 |
| August | 86°F (30°C) | 65°F (18°C) | 76°F (24°C) | 4.7" | 0.0 | 9.8 |
| September | 81°F (27°C) | 58°F (15°C) | 70°F (21°C) | 3.6" | 0.0 | 3.7 |
| October | 72°F (22°C) | 46°F (8°C) | 59°F (15°C) | 3.1" | 2.9 | 0.2 |
| November | 62°F (16°C) | 34°F (1°C) | 48°F (9°C) | 3.4" | 14.6 | 0.0 |
| December | 54°F (12°C) | 29°F (-2°C) | 41°F (5°C) | 4.0" | 19.9 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 88°F around July 12, short of 90°F on every date, while 99 dates carry a normal low at or below freezing, the coldest 26°F near January 19.
The freezing stretch
The normal low stays at or below 32°F into March 2, then returns to freezing around November 25, covering 99 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is July 27, when 33% of years recorded at least a hundredth of an inch. The driest is October 18 at 23%. Summed across the calendar, that is about 105 wet dates a year.
The widest day
April 13 carries the biggest normal gap between afternoon and dawn, 29°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Ninety Nine Island.
Monthly Precipitation
Average monthly rainfall
8.7 days with precipitation
8.9 days with precipitation
10.0 days with precipitation
8.7 days with precipitation
8.6 days with precipitation
9.6 days with precipitation
9.8 days with precipitation
9.1 days with precipitation
7.1 days with precipitation
6.6 days with precipitation
7.6 days with precipitation
9.5 days with precipitation
Ninety Nine Island spreads its precipitation across the year
Neither half of the year dominates here: June through August take 28% of the annual total and December through February 24%, with neither reaching the 35% that would mark a distinct wet season. Ninety Nine Island has no dry season to plan around, though it does carry a 38°F seasonal spread.
The gap between the wettest and driest month still matters: August averages 4.7" and October 3.1". The three wettest months together take 29% of the year, against the 25% a perfectly flat distribution would give them.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. "Spread across the year" means neither the June-August nor the December-February share reaches 35%; it describes an average year, not the variability of any single one.
When it rains in Ninety Nine Island, it arrives in quantity
45.3" of precipitation falls across only about 104 wet days here, averaging 0.43 inches each. Fewer days carry more water: the year's total is delivered in comparatively heavy events rather than persistent damp.
- Days with measurable precipitation
- about 104 a year, 29% of all days
- Average depth per wet day
- 0.43 inches
- Most wet days
- March, about 10
- Fewest wet days
- October, about 7
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, and a per-day average is not a forecast of any individual storm.
Frost Dates & Growing Season
First Fall Freeze
October 24
50% probability date
Last Spring Freeze
April 20
50% probability date
Growing Season
187 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
3,789
Higher = more heating needed
Cooling Degree Days
1,235
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside SC closest to Ninety Nine Island on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (58°F here).
- Albuquerque, NM 58°F · 0.0°F off
- Brentwood, TN 58°F · 0.0°F off
- Buffalo, OK 58°F · 0.0°F off
- Lenoir, NC 58°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (45.3" here), excluding temperature-peer places.
- Biglerville, PA 45.3" · 0.0" off
- Mineola, NY 45.3" · 0.0" off
- Ashland, VA 45.3" · 0.0" off
- Pawhuska, OK 45.3" · 0.0" off
Data-derived climate profile
How Ninety Nine Island's climate pattern fits together
heating led · wet · mid swing
Ninety Nine Island's energy balance leans toward cold weather: 3,789 annual heating degree days against 1,235 for cooling. Its 38.0°F seasonal range still makes the monthly rows more useful than the annual average alone.
Ninety Nine Island's frost-free season lasts about 187 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
July and January mark the typical warm and cold ends of the calendar in Ninety Nine Island's middle-range seasonal profile. The measured spread is 38.0°F. The annual average is 58°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Alongside its heating load, Ninety Nine Island carries 45.3 inches of precipitation in a normal year, inside PlainClimate's wet range. Snowfall is not added to the interpretation because its annual value is missing. That distinction matters because a wet annual total can arrive as rain, snow, or a mixture at different times.
These labels group NOAA 1991-2020 normals from Ninety Nine Island's primary station, so the winter figures are a thirty-year average and not a floor: a single hard season can run well below them. Treat each band as a descriptive range for Ninety Nine Island, not an official NOAA class or a year-ahead forecast.
Questions about Ninety Nine Island's climate
How much rain does Ninety Nine Island get? ▼
How many days above 90°F does Ninety Nine Island get? ▼
How much energy does heating and cooling require in Ninety Nine Island? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Ninety Nine Island's primary station: NINETY NINE IS (USC00386293). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The conservative exact name-and-state crosswalk finds no Census place match, so PlainClimate treats this as a station-mapped location and does not claim it is a municipality. No exact Gazetteer row for Ninety Nine Island; facility counts that depend on place identity are therefore an upper bound, not a municipal census.
On this page every temperature, precipitation, and derived score for Ninety Nine Island comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.