Union, MO Climate: Temperature & Rain by Month
Pulled from NOAA NCEI 1991–2020 normals →: climate measurements used in PlainClimate's documented score
30-year climate normals (1991-2020) from Union's primary NOAA station, UNION.
The climate verdict for Union
Union, Missouri has a mixed annual climate rather than one dominant extreme. Its NOAA normal shows an annual average of 57°F. It scores 78/100 for climate comfort (good), putting it in the top third of station-mapped location scores and exceeding 72% of them.
- 57°F
- annual average temperature (NOAA normal)
- 78/100
- comfort score, above 72% of station-mapped location scores
- 45.0"
- annual precipitation · 14" snow
- 195 days
- frost-free days per growing season
Union: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00238515 · Union, MO 57°F mean · 45.0" precip
TEMP-MILD · RANK-UPPER · PHOTO-FINISH · PRCP-MID · SWING-WIDE · COMF-TOP · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-MILD 57°F
- RANK-UPPER #4,528
- PHOTO-FINISH ≈ Wappapello Dam
- PRCP-MID 45.0"
- SWING-WIDE 46°F
- COMF-TOP 78/100
- LOAD-HEAT 4,400 HDD
- STN-1 USC00238515
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Wappapello Dam, MO ( -0.1 °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 MO station list.
- Union (this station) 57°F
- Cold Arnett, OK 57°F
- Hot Fairfield Radio…, IL 57°F
- Near Wappapello Dam, MO 57°F
- Near Advance, MO 57°F
Climate Living Index · Union
Union: 60/100 · grade C
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 78/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Annual temperature balance | 56.9°F · 10.6° from 67.5°F | 66/100 · C |
| Precipitation balance | 45.0 in · 10.0 from 35 in | 65/100 · C |
| Frost-free season | 195 days/year | 61/100 · C |
| Snowfall burden | 14.4 inches/year | 57/100 · C |
| Normal heat + freeze calendar | 144 calendar days | 51/100 · D |
Union · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Union is a temperate Köppen climate: Cfa
Coldest-month mean 33.0°F and warmest-month mean 79.0°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
- 79.0°F
- Coldest month
- 33.0°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 · heating-led 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
- 66th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- 68th percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- 64th percentile swing
- Typical seasonal amplitude 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
78 Top 28% score exceeds 72% 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%). This entry sits in this band.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 43°F (6°C) | 23°F (-5°C) | 33°F (1°C) | 2.7" | 4.7" | 25.1 | 0.0 |
| February | 48°F (9°C) | 26°F (-3°C) | 37°F (3°C) | 2.5" | 4.1" | 19.7 | 0.0 |
| March | 59°F (15°C) | 35°F (2°C) | 47°F (8°C) | 3.9" | 1.8" | 14.1 | 0.0 |
| April | 70°F (21°C) | 45°F (7°C) | 58°F (14°C) | 5.0" | 0.2" | 3.8 | 0.3 |
| May | 78°F (26°C) | 55°F (13°C) | 67°F (19°C) | 4.8" | 0.0" | 0.1 | 1.4 |
| June | 86°F (30°C) | 63°F (17°C) | 75°F (24°C) | 4.2" | 0.0" | 0.0 | 8.8 |
| July | 91°F (33°C) | 67°F (20°C) | 79°F (26°C) | 4.7" | 0.0" | 0.0 | 17.0 |
| August | 89°F (32°C) | 66°F (19°C) | 78°F (25°C) | 3.8" | 0.0" | 0.0 | 16.2 |
| September | 82°F (28°C) | 57°F (14°C) | 69°F (21°C) | 3.6" | 0.0" | 0.1 | 5.3 |
| October | 70°F (21°C) | 46°F (8°C) | 58°F (14°C) | 3.3" | 0.0" | 3.0 | 0.6 |
| November | 57°F (14°C) | 35°F (2°C) | 46°F (8°C) | 3.7" | 0.7" | 12.8 | 0.0 |
| December | 46°F (8°C) | 27°F (-3°C) | 37°F (3°C) | 2.7" | 2.9" | 21.9 | 0.0 |
The year, day by day
Union works both ends of the calendar. Normal highs climb to 91°F by July 14 and hold at or above 90°F on 42 dates, then normal lows drop to freezing or below on 102 dates, bottoming at 22°F around January 21.
When the heat sits
Normal highs reach 90°F from July 3 through August 13, covering 42 dates. The broader mild season, normal highs of 70°F or more, runs April 14 to October 16.
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 March 4, then returns to freezing around November 24, covering 102 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 May 2, when 42% of years recorded at least a hundredth of an inch. The driest is October 1 at 24%. Summed across the calendar, that is about 109 wet dates a year.
The widest day
April 7 carries the biggest normal gap between afternoon and dawn, 26°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: 4.7"
8.8 days with precipitation
Snow: 4.1"
7.3 days with precipitation
Snow: 1.8"
9.9 days with precipitation
Snow: 0.2"
11.0 days with precipitation
12.4 days with precipitation
9.5 days with precipitation
8.2 days with precipitation
8.1 days with precipitation
7.6 days with precipitation
7.7 days with precipitation
Snow: 0.7"
8.9 days with precipitation
Snow: 2.9"
8.8 days with precipitation
Union spreads its precipitation across the year
Neither half of the year dominates here: June through August take 29% of the annual total and December through February 17%, 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 wide 46°F gap between its warmest and coldest month.
The gap between the wettest and driest month still matters: April averages 5.0" and February 2.5". The three wettest months together take 32% 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
45.0" of precipitation falls across only about 108 wet days here, averaging 0.42 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 108 a year, 30% of all days
- Average depth per wet day
- 0.42 inches
- Most wet days
- May, about 12
- Fewest wet days
- February, 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.
Winter brings real snow to Union
Union averages 14.4 inches of snowfall a year, with January the snowiest month on the normals, spread across roughly 10 days that record measurable snow. That is depth accumulating on the ground, which is why it can exceed the annual precipitation figure: precipitation counts the liquid the snow melts down to, and fresh snow is mostly air.
- Annual snowfall: 14.4 inches of depth.
- Days recording measurable snow: about 10 a year.
- At a rough ten-to-one melt ratio, snow accounts for on the order of 3% of the year's precipitation.
NOAA 1991-2020 normals. The ten-to-one ratio is a convention, not a measurement: real ratios vary with temperature, so treat the share as an order of magnitude rather than an exact split.
Frost Dates & Growing Season
First Fall Freeze
October 23
50% probability date
Last Spring Freeze
April 11
50% probability date
Growing Season
195 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
4,400
Higher = more heating needed
Cooling Degree Days
1,485
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Nationwide similar cities
Other rankable U.S. places outside MO 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 (57°F here).
- Ashland, KS 57°F · 0.0°F off
- Beaver Dam, KY 57°F · 0.0°F off
- Benton, KY 57°F · 0.0°F off
- Clearlake, CA 57°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (45.0" here), excluding temperature-peer places.
- Tavernier, FL 45.0" · 0.0" off
- Baltimore, MD 45.0" · 0.0" off
- Marlinton, WV 44.9" · 0.0" off
- Upper Marlboro, MD 45.0" · 0.0" off
Snow and freeze rhythm
When cold and snow define Union
heating led · moderate · mid swing
Union's energy balance leans toward cold weather: 4,400 annual heating degree days against 1,485 for cooling. Its 46.0°F seasonal range still makes the monthly rows more useful than the annual average alone.
Union's frost-free season lasts about 195 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
-
1. Union coldest normal
January
The monthly mean of 33°F (1°C) sits near freezing, so cold nights and above-freezing afternoons share the same month.
-
2. Union typical freeze period
January through December
The station reports average freezing days from January through December.
-
3. Union snow peak
January
Union averages 14.4 inches of snow a year, with January the snowiest month on the normals.
Questions about Union's climate
How much snow 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 (USC00238515). 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 2974626). 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.