Swannanoa, North Carolina climate: Normal weather by month, frost dates and records
Swannanoa's normal year runs from 25°F January nights to 76°F July afternoons, with 53.0 inches of precipitation and 29 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.8°C, January lows of −4°C, July highs of 24°C, 1,346 mm of precipitation a year.
- NOAA stationSwannanoa (2 mi SSE)
- Station IDUSC00318448
- Location35.57°N 82.39°W
- Elevation4,320 ft (1,317 m)
- From the center2 miles
- Population (census place)6,043
On October 23, the normal high in Swannanoa is 59°F and the normal low 42°F, and the chance of measurable rain or snow is 29%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Swannanoa.
- Jan 41° 25°
- Feb 44° 27°
- Mar 52° 33°
- Apr 62° 42°
- May 69° 50°
- Jun 73° 57°
- Jul 76° 61°
- Aug 75° 60°
- Sep 70° 54°
- Oct 61° 44°
- Nov 52° 34°
- Dec 44° 28°
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 Swannanoa each month?
July is the warmest month, with normal highs of 76°F; January the coldest, with normal lows of 25°F. The most precipitation falls in September (5.16 in), the least in February (3.70 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 41°F | 25°F | 32.7°F | 4.55 | 6.8 | 13 | <1 | 22 | 10 h |
| February | 44°F | 27°F | 35.5°F | 3.70 | 5.8 | 11 | <1 | 19 | 10 h 50 min |
| March | 52°F | 33°F | 42.4°F | 4.66 | 6.3 | 13 | <1 | 16 | 11 h 50 min |
| April | 62°F | 42°F | 51.7°F | 4.61 | 2.5 | 12 | <1 | 7 | 13 h |
| May | 69°F | 50°F | 59.5°F | 4.12 | 0.7 | 12 | <1 | 1 | 14 h |
| June | 73°F | 57°F | 65.1°F | 4.43 | 0.0 | 15 | <1 | <1 | 14 h 30 min |
| July | 76°F | 61°F | 68.4°F | 4.89 | 0.0 | 14 | <1 | <1 | 14 h 20 min |
| August | 75°F | 60°F | 67.0°F | 4.64 | 0.0 | 13 | <1 | <1 | 13 h 30 min |
| September | 70°F | 54°F | 61.9°F | 5.16 | 0.0 | 10 | <1 | <1 | 12 h 30 min |
| October | 61°F | 44°F | 52.9°F | 3.79 | 0.1 | 9 | <1 | 3 | 11 h 20 min |
| November | 52°F | 34°F | 42.9°F | 4.11 | 1.1 | 10 | <1 | 13 | 10 h 20 min |
| December | 44°F | 28°F | 36.1°F | 4.34 | 5.2 | 12 | <1 | 21 | 9 h 50 min |
| Year (annual) | 60°F | 43°F | 51.4°F | 53.00 | 28.5 | 142 | <1 | 102 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 5°C | −4°C | 0.4°C | 116 mm | 17 cm |
| February | 7°C | −3°C | 1.9°C | 94 mm | 15 cm |
| March | 11°C | 0°C | 5.8°C | 118 mm | 16 cm |
| April | 17°C | 5°C | 10.9°C | 117 mm | 6 cm |
| May | 21°C | 10°C | 15.3°C | 105 mm | 2 cm |
| June | 23°C | 14°C | 18.4°C | 113 mm | 0 cm |
| July | 24°C | 16°C | 20.2°C | 124 mm | 0 cm |
| August | 24°C | 15°C | 19.4°C | 118 mm | 0 cm |
| September | 21°C | 12°C | 16.6°C | 131 mm | 0 cm |
| October | 16°C | 7°C | 11.6°C | 96 mm | 0 cm |
| November | 11°C | 1°C | 6.1°C | 104 mm | 3 cm |
| December | 7°C | −2°C | 2.3°C | 110 mm | 13 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00318448; 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 Swannanoa?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September has the fewest days with rain (10).
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 USC00318448.
When is the last frost in Swannanoa?
In Swannanoa, the last spring frost (32°F) comes after April 22 in half of years and after May 11 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 221 year in 10 after May 11; 9 in 10 after April 5
- First autumn frost, half of years before
- October 241 year in 10 before October 11; 9 in 10 before November 6
NOAA puts the median frost-free season at 184 days, and the season without a hard freeze (28°F) at 205 days.
A hard freeze (28°F) comes after April 9 in half of springs and before November 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Swannanoa in zone 7a in ZIP code 28778. By the map's own method, the average of each year's coldest night over 1991-2020, Swannanoa's NOAA station is in zone 6b: the coldest night of a typical year reaches −2°F (17 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 North Carolina · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00318448; 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 in Swannanoa?
In a normal year in Swannanoa, a 90°F day is rare, 102 nights fall to 32°F or colder and 142 days bring measurable precipitation.
- Days at 90°F or more
- fewer than 1a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 102a normal year
- Days that stay below freezing
- 19high of 32°F or less
- Days with 0.01 inch of precipitation
- 142a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1984) is 88°F, on July 21, 1986; the lowest is −26°F, on January 21, 1985.
The wettest calendar year on that record is 1989, with 66.06 in; the snowiest season is 1986–87, with 56.2 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00318448; records: ACIS (NOAA Regional Climate Centers), station USC00318448. Records use complete months only; a month missing more than three days is left out.
How sunny is Swannanoa?
Over a year 74% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Swannanoa, 4.4 kWh per square metre a day. November is the sunniest month (77%) and February the cloudiest (70%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 73% | 2.6 |
| February | 70% | 3.3 |
| March | 71% | 4.3 |
| April | 74% | 5.4 |
| May | 74% | 5.9 |
| June | 76% | 6.2 |
| July | 75% | 5.8 |
| August | 76% | 5.4 |
| September | 76% | 4.7 |
| October | 77% | 3.8 |
| November | 77% | 3.0 |
| December | 71% | 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 much heating and cooling does Swannanoa need?
A normal year in Swannanoa brings 5,274 heating degree days, 2% fewer than the median U.S. place (5,373), and 325 cooling degree days, 64% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,621 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,000 | 0 |
| February | 826 | 0 |
| March | 699 | 0 |
| April | 404 | 5 |
| May | 191 | 22 |
| June | 60 | 61 |
| July | 11 | 117 |
| August | 27 | 89 |
| September | 121 | 29 |
| October | 377 | 2 |
| November | 663 | 0 |
| December | 896 | 0 |
| Year (annual) | 5,274 | 325 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00318448. 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.
How does Swannanoa's climate compare?
Swannanoa is warmer than 6 of the other 130 places with their own NOAA record in North Carolina, and wetter than 82. Across the 7,247 U.S. stations with normals, its annual mean of 51.4°F is warmer than 47%.
In the Köppen classification computed from these normals, Swannanoa is Cfb: temperate, no dry season, warm 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 Swannanoa share this climate record?
2 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.
- Fairview, NC2,327 people · 4 mi S
- Gerton, NC196 people · 7 mi S
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 Swannanoa's climate
What is the coldest month in Swannanoa?
January, with a normal high of 41°F and a normal low of 25°F. The warmest is July (76°F by day, 61°F at night).
Does it snow in Swannanoa?
Yes: 29 inches in a normal year, falling on 25 days with 0.1 inch or more, the most in January (6.8 inches).
What is the rainiest month in Swannanoa?
September, with 5.16 in of precipitation in a normal year; the driest is February with 3.70 in.
What plant hardiness zone is Swannanoa in?
The USDA's 2023 map puts Swannanoa in zone 7a in ZIP code 28778. By the same method at Swannanoa's NOAA station, the coldest night of a typical year reaches −2°F (17 years, 1991-2020): zone 6b.
How late can frost come in Swannanoa?
In half of years the last 32°F night comes after April 22; in one year in ten it comes after May 11. Waiting until May 11 leaves about a one-in-ten chance of a later frost.
Nearby and next
- North Carolina climateThe statewide normals and every place in the state
- Black Mountain, NC2 miles from this station, 55.4°F a year
- North Fork 2, NC7 miles from this station, 56.2°F a year
- Bent Creek, NC13 miles from this station, 54.4°F a year
- Asheville, NC13 miles from this station, 57.3°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made