Union, West Virginia climate: Normal weather by month, frost dates and records
Union's normal year runs from 22°F January nights to 84°F July afternoons, with 38.8 inches of precipitation and 24 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.6°C, January lows of −5°C, July highs of 29°C, 985 mm of precipitation a year.
- NOAA stationUnion (3 mi SSE)
- Station IDUSC00469011
- Location37.54°N 80.53°W
- Elevation2,110 ft (643 m)
- Population417
On October 24, the normal high in Union is 65°F and the normal low 37°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 Union.
- Jan 42° 22°
- Feb 47° 24°
- Mar 55° 30°
- Apr 66° 39°
- May 74° 48°
- Jun 81° 57°
- Jul 84° 61°
- Aug 83° 59°
- Sep 78° 52°
- Oct 68° 40°
- Nov 56° 31°
- Dec 46° 25°
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 Union each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 22°F. The most precipitation falls in May (4.60 in), the least in February (2.28 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 42°F | 22°F | 32.3°F | 2.65 | 6.3 | 10 | <1 | 25 | 9 h 50 min |
| February | 47°F | 24°F | 35.3°F | 2.28 | 5.9 | 10 | <1 | 24 | 10 h 50 min |
| March | 55°F | 30°F | 42.5°F | 3.31 | 5.1 | 12 | <1 | 19 | 11 h 50 min |
| April | 66°F | 39°F | 52.5°F | 3.50 | 0.4 | 13 | <1 | 9 | 13 h 10 min |
| May | 74°F | 48°F | 61.1°F | 4.60 | 0.0 | 15 | <1 | 2 | 14 h 10 min |
| June | 81°F | 57°F | 69.1°F | 3.84 | 0.0 | 13 | 1 | <1 | 14 h 40 min |
| July | 84°F | 61°F | 72.4°F | 3.76 | 0.0 | 12 | 2 | <1 | 14 h 30 min |
| August | 83°F | 59°F | 71.2°F | 3.25 | 0.0 | 11 | 2 | <1 | 13 h 40 min |
| September | 78°F | 52°F | 64.7°F | 3.60 | 0.0 | 10 | 1 | 1 | 12 h 30 min |
| October | 68°F | 40°F | 53.5°F | 2.56 | 0.1 | 9 | <1 | 10 | 11 h 20 min |
| November | 56°F | 31°F | 43.3°F | 2.52 | 0.7 | 9 | <1 | 19 | 10 h 10 min |
| December | 46°F | 25°F | 35.7°F | 2.90 | 5.5 | 11 | <1 | 26 | 9 h 40 min |
| Year (annual) | 65°F | 41°F | 52.8°F | 38.77 | 24.0 | 135 | 5 | 134 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 6°C | −5°C | 0.2°C | 67 mm | 16 cm |
| February | 8°C | −4°C | 1.8°C | 58 mm | 15 cm |
| March | 13°C | −1°C | 5.8°C | 84 mm | 13 cm |
| April | 19°C | 4°C | 11.4°C | 89 mm | 1 cm |
| May | 23°C | 9°C | 16.2°C | 117 mm | 0 cm |
| June | 27°C | 14°C | 20.6°C | 98 mm | 0 cm |
| July | 29°C | 16°C | 22.4°C | 96 mm | 0 cm |
| August | 29°C | 15°C | 21.8°C | 83 mm | 0 cm |
| September | 25°C | 11°C | 18.2°C | 91 mm | 0 cm |
| October | 20°C | 4°C | 11.9°C | 65 mm | 0 cm |
| November | 13°C | −1°C | 6.3°C | 64 mm | 2 cm |
| December | 8°C | −4°C | 2.1°C | 74 mm | 14 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00469011; 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 Union?
Normal highs sit between 65°F and 85°F in April, May, June, July, August, September and October. Of those, October has the fewest days with rain (9).
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 USC00469011.
When is the last frost in Union?
In Union, the last spring frost (32°F) comes after April 30 in half of years and after May 17 in one year in ten; the first autumn frost comes before October 12 in half of years and before September 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
- April 301 year in 10 after May 17; 9 in 10 after April 12
- First autumn frost, half of years before
- October 121 year in 10 before September 30; 9 in 10 before October 26
NOAA puts the median frost-free season at 165 days, and the season without a hard freeze (28°F) at 188 days.
A hard freeze (28°F) comes after April 15 in half of springs and before October 22 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Union in zone 6b in ZIP code 24983, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Union's NOAA station is in zone 6b: the coldest night of a typical year reaches −2°F (18 complete years).
Frost dates for every NOAA station in West Virginia · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00469011; 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 Union?
In a normal year in Union, 5 days a year reach 90°F, 134 nights fall to 32°F or colder and 135 days bring measurable precipitation.
- Days at 90°F or more
- 5a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 134a normal year
- Days that stay below freezing
- 17high of 32°F or less
- Days with 0.01 inch of precipitation
- 135a normal year
- Days with 1 inch of snow or more
- 8a normal year
The highest temperature in this station's record (since 1902) is 101°F, on July 15, 1954; the lowest is −35°F, on December 30, 1917.
The wettest calendar year on that record is 2003, with 54.21 in; the snowiest season is 1995–96, with 74.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00469011; records: ACIS (NOAA Regional Climate Centers), station USC00469011. Records use complete months only; a month missing more than three days is left out.
How sunny is Union?
Over a year 71% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Union, 4.1 kWh per square metre a day. August is the sunniest month (76%) and January the cloudiest (65%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 65% | 2.2 |
| February | 65% | 2.9 |
| March | 67% | 3.9 |
| April | 71% | 5.1 |
| May | 70% | 5.5 |
| June | 75% | 6.1 |
| July | 75% | 5.9 |
| August | 76% | 5.3 |
| September | 74% | 4.4 |
| October | 72% | 3.4 |
| November | 73% | 2.6 |
| December | 65% | 1.9 |
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 Union need?
A normal year in Union brings 5,137 heating degree days, 4% fewer than the median U.S. place (5,373), and 725 cooling degree days, 20% 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 3,164 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,013 | 0 |
| February | 832 | 0 |
| March | 698 | 1 |
| April | 384 | 9 |
| May | 167 | 46 |
| June | 28 | 152 |
| July | 3 | 234 |
| August | 6 | 200 |
| September | 86 | 75 |
| October | 362 | 7 |
| November | 650 | 1 |
| December | 908 | 0 |
| Year (annual) | 5,137 | 725 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00469011. 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 Union's climate compare?
Union is warmer than 31 of the other 62 places with their own NOAA record in West Virginia, and wetter than 5. Across the 7,247 U.S. stations with normals, its annual mean of 52.8°F is warmer than 53%.
In the Köppen classification computed from these normals, Union 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.
Questions about Union's climate
What is the coldest month in Union?
January, with a normal high of 42°F and a normal low of 22°F. The warmest is July (84°F by day, 61°F at night).
Does it snow in Union?
Yes: 24 inches in a normal year, falling on 15 days with 0.1 inch or more, the most in January (6.3 inches).
What is the rainiest month in Union?
May, with 4.60 in of precipitation in a normal year; the driest is February with 2.28 in.
What plant hardiness zone is Union in?
The USDA's 2023 map puts Union in zone 6b in ZIP code 24983, the nearest ZIP area. By the same method at Union's NOAA station, the coldest night of a typical year reaches −2°F (18 years, 1991-2020): zone 6b.
How late can frost come in Union?
In half of years the last 32°F night comes after April 30; in one year in ten it comes after May 17. Waiting until May 17 leaves about a one-in-ten chance of a later frost.
Nearby and next
- West Virginia climateThe statewide normals and every place in the state
- Alderson, WV14 miles from this station, 52.8°F a year
- Pearisburg, VA21 miles from this station, 52.6°F a year
- Bluestone Lake, WV21 miles from this station, 55.0°F a year
- White Sulphur Springs, WV21 miles from this station, 51.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made