Union, SC Climate: Temperature & Rain by Month
Annual temperature and rainfall from NOAA NCEI's 1991–2020 normals →; comfort score computed by PlainClimate
30-year climate normals (1991-2020) from Union's primary NOAA station, UNION 8 S.
The climate verdict for Union
Water is the standout signal in Union, South Carolina: 45.3 inches of precipitation in a normal year. Against that wet profile, NOAA records an annual average of 60°F. It scores 93/100 for climate comfort (excellent), putting it in the top third of station-mapped location scores and exceeding 93% of them.
- 60°F
- annual average temperature (NOAA normal)
- 93/100
- comfort score, above 93% of station-mapped location scores
- 45.3"
- annual precipitation · 2" snow
- 207 days
- growing season, frost-free days
Union: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00388786 · Union, SC 60°F mean · 45.3" precip
TEMP-MILD · RANK-UPPER · PHOTO-FINISH · PRCP-MID · SWING-MID · COMF-TOP · LOAD-MIX · STN-1 · BOOK-FULL
- TEMP-MILD 60°F
- RANK-UPPER #5,214
- PHOTO-FINISH ≈ Bagdad
- PRCP-MID 45.3"
- SWING-MID 38°F
- COMF-TOP 93/100
- LOAD-MIX H/C balanced
- STN-1 USC00388786
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Bagdad, AZ (+ 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.
- Union (this station) 60°F
- Hot Chester, SC 60°F
- Near Bagdad, AZ 60°F
- Near Ben Lomond, CA 60°F
- Near Chatham Wtp, NC 60°F
Climate Living Index · Union
Union: 74/100 · grade B
Union publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Union, not an official NOAA rating. Rankings still use Comfort Score 93/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Annual temperature balance | 60.4°F · 7.1° from 67.5°F | 78/100 · B |
| Normal heat + freeze calendar | 95 calendar days | 77/100 · B |
| Snowfall burden | 1.9 inches/year | 76/100 · B |
| Frost-free season | 207 days/year | 69/100 · C |
| Precipitation balance | 45.3 in · 10.3 from 35 in | 64/100 · C |
Union · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Union is a temperate Köppen climate: Cfa
Coldest-month mean 41.0°F and warmest-month mean 79.3°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
- 79.3°F
- Coldest month
- 41.0°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 · balanced station
Where Union sits across the climate record
Three NOAA fields for Union's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Top 24% warmest
- Among 6,861 stations, Union sits in the warmer third of annual means.
- Annual precipitation
- 69th percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- Narrower than 72%
- Warmest-to-coldest month gap for Union is compact versus 6,861 complete station-years.
How Union compares across U.S. station-mapped locations
Union's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
93 Top 7% score exceeds 93% 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%). Below this entry.
- 90–100: 564 station-mapped locations (9%). This entry sits in this band.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Union's measured station temperature trend
MethodologyAcross 61 complete annual observations from 1950 to 2025, UNION 8 S warmed at a fitted rate of 0.04°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Union primary station fitted change +0.04 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 53°F (12°C) | 29°F (-2°C) | 41°F (5°C) | 4.2" | 0.9" | 20.8 | 0.0 |
| February | 57°F (14°C) | 32°F (0°C) | 45°F (7°C) | 3.6" | 0.6" | 17.1 | 0.0 |
| March | 65°F (18°C) | 38°F (3°C) | 51°F (11°C) | 4.3" | 0.4" | 11.7 | 0.0 |
| April | 74°F (23°C) | 47°F (8°C) | 60°F (16°C) | 3.8" | 0.0" | 2.7 | 0.6 |
| May | 81°F (27°C) | 55°F (13°C) | 68°F (20°C) | 3.1" | 0.0" | 0.0 | 3.0 |
| June | 87°F (31°C) | 65°F (18°C) | 76°F (24°C) | 4.1" | 0.0" | 0.0 | 11.4 |
| July | 90°F (32°C) | 68°F (20°C) | 79°F (26°C) | 3.7" | 0.0" | 0.0 | 19.0 |
| August | 89°F (32°C) | 67°F (20°C) | 78°F (26°C) | 4.0" | 0.0" | 0.0 | 14.5 |
| September | 83°F (28°C) | 61°F (16°C) | 72°F (22°C) | 3.4" | 0.0" | 0.0 | 6.6 |
| October | 74°F (23°C) | 48°F (9°C) | 61°F (16°C) | 3.3" | 0.0" | 2.0 | 0.4 |
| November | 63°F (17°C) | 37°F (3°C) | 50°F (10°C) | 3.6" | 0.0" | 12.7 | 0.0 |
| December | 55°F (13°C) | 32°F (0°C) | 44°F (6°C) | 4.3" | 0.0" | 19.5 | 0.0 |
The year, day by day
Union works both ends of the calendar. Normal highs climb to 91°F by July 10 and hold at or above 90°F on 32 dates, then normal lows drop to freezing or below on 63 dates, bottoming at 29°F around January 11.
When the heat sits
Normal highs reach 90°F from July 1 through August 1, covering 32 dates. The broader mild season, normal highs of 70°F or more, runs April 3 to October 26.
This counts calendar dates whose 1991–2020 normal high reaches 90°F. It is a smaller number than the 90°F+ day counts in the monthly table above, which measure how often the threshold was actually crossed in a typical year. A date can average 88°F and still exceed 90°F in half of all years.
The freezing stretch
The normal low stays at or below 32°F into February 14, then returns to freezing around December 14, covering 63 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 December 22, when 33% of years recorded at least a hundredth of an inch. The driest is October 17 at 23%. Summed across the calendar, that is about 105 wet dates a year.
The widest day
April 5 carries the biggest normal gap between afternoon and dawn, 28°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Union.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 0.9"
9.4 days with precipitation
Snow: 0.6"
8.8 days with precipitation
Snow: 0.4"
9.6 days with precipitation
8.4 days with precipitation
7.9 days with precipitation
9.5 days with precipitation
9.4 days with precipitation
9.2 days with precipitation
7.3 days with precipitation
6.5 days with precipitation
7.9 days with precipitation
10.0 days with precipitation
Union spreads its precipitation across the year
Neither half of the year dominates here: June through August take 26% of the annual total and December through February 27%, with neither reaching the 35% that would mark a distinct wet season. Union has no dry season to plan around, though it does carry a 38.3°F seasonal spread.
The gap between the wettest and driest month still matters: March averages 4.3" and May 3.1". The three wettest months together take 28% 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 Union, it arrives in quantity
45.3" of precipitation falls across only about 104 wet days here, averaging 0.44 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, 28% of all days
- Average depth per wet day
- 0.44 inches
- Most wet days
- December, 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.
Snow reaches Union, but rarely amounts to much
The normals record 1.9 inches of snow a year here, most likely in January. That is a real but marginal amount: enough that snow is part of the local record, not enough to define the winter.
A figure in this range usually reflects a handful of events that melt quickly rather than a season of accumulation; about 1 days a year record any measurable snow at all.
NOAA 1991-2020 normals. An average across thirty years can smooth away a single heavy winter, so a small annual figure does not mean a significant snowfall is impossible.
Frost Dates & Growing Season
First Fall Freeze
October 30
50% probability date
Last Spring Freeze
April 6
50% probability date
Growing Season
207 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
3,296
Higher = more heating needed
Cooling Degree Days
1,649
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside SC closest to Union 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 (60°F here).
- Bagdad, AZ 60°F · 0.0°F off
- Ben Lomond, CA 60°F · 0.0°F off
- Cushing, OK 60°F · 0.0°F off
- Hollis, OK 60°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (45.3" here), excluding temperature-peer places.
- Buffalo, MO 45.3" · 0.0" off
- Slippery Rock, PA 45.2" · 0.0" off
- Harrisburg, PA 45.2" · 0.0" off
- Norwich, NY 45.3" · 0.0" off
Data-derived climate profile
How Union's climate pattern fits together
mixed demand · wet · mid swing
Water is prominent even though neither heating nor cooling wholly defines the record. Union averages 45.3 inches of precipitation a year. Annual snowfall totals 1.9 inches. The monthly table supplies the seasonal distribution hidden by that annual total.
July and January mark the typical warm and cold ends of the calendar in Union's middle-range seasonal profile. The measured spread is 38.3°F. The annual average is 60°F. Neither the annual mean nor one extreme month represents the full calendar on its own.
Heating and cooling both register in Union's normal, at 3,296 and 1,649 degree days respectively. Neither total exceeds the other by more than two to one, so the record is better read as a mixed-demand calendar than as heating-led or cooling-led.
A roughly 207-day frost-free season sits inside this mixed heating-and-cooling profile. Start and end dates matter because both sides of the thermostat register during a normal year.
These labels group NOAA 1991-2020 normals from Union's primary station, where heating and cooling demand are close enough that neither season sets the character on its own. On a balanced station like Union, the bands are descriptive ranges rather than an official NOAA classification or a forecast.
Questions about Union's climate
How much rain does Union get? ▼
How many days above 90°F does Union get? ▼
How much energy does heating and cooling require in Union? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Union's primary station: UNION 8 S (USC00388786). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 4573105). Match rule for Union: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for Union 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.