Union City, Tennessee climate: Normal weather by month, frost dates and records
Union City's normal year runs from 27°F January nights to 88°F July afternoons, with 53.8 inches of precipitation and 6 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 14.4°C, January lows of −3°C, July highs of 31°C, 1,366 mm of precipitation a year.
- NOAA stationUnion City
- Station IDUSC00409219
- Location36.39°N 89.03°W
- Elevation350 ft (107 m)
- Population10,876
On October 23, the normal high in Union City is 69°F and the normal low 43°F, and the chance of measurable rain or snow is 30%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Union City.
- Jan 45° 27°
- Feb 49° 30°
- Mar 59° 37°
- Apr 69° 47°
- May 78° 57°
- Jun 86° 66°
- Jul 88° 69°
- Aug 88° 66°
- Sep 83° 58°
- Oct 72° 46°
- Nov 59° 36°
- Dec 48° 30°
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 City each month?
July is the warmest month, with normal highs of 88°F; January the coldest, with normal lows of 27°F. The most precipitation falls in May (5.56 in), the least in August (3.34 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 45°F | 27°F | 35.7°F | 3.97 | 2.1 | 12 | <1 | 22 | 10 h |
| February | 49°F | 30°F | 39.4°F | 4.64 | 1.7 | 11 | <1 | 18 | 10 h 50 min |
| March | 59°F | 37°F | 48.0°F | 5.23 | 1.0 | 13 | <1 | 11 | 11 h 50 min |
| April | 69°F | 47°F | 57.9°F | 5.22 | 0.0 | 12 | <1 | 2 | 13 h 10 min |
| May | 78°F | 57°F | 67.7°F | 5.56 | 0.0 | 12 | 1 | <1 | 14 h |
| June | 86°F | 66°F | 75.8°F | 4.41 | 0.0 | 10 | 9 | <1 | 14 h 40 min |
| July | 88°F | 69°F | 78.5°F | 4.05 | 0.0 | 9 | 14 | <1 | 14 h 30 min |
| August | 88°F | 66°F | 76.9°F | 3.34 | 0.0 | 8 | 13 | <1 | 13 h 40 min |
| September | 83°F | 58°F | 70.3°F | 3.81 | 0.0 | 8 | 6 | <1 | 12 h 30 min |
| October | 72°F | 46°F | 58.9°F | 3.96 | 0.1 | 8 | <1 | 2 | 11 h 20 min |
| November | 59°F | 36°F | 47.4°F | 4.43 | 0.2 | 10 | <1 | 12 | 10 h 20 min |
| December | 48°F | 30°F | 39.0°F | 5.17 | 0.7 | 11 | <1 | 20 | 9 h 40 min |
| Year (annual) | 69°F | 47°F | 57.9°F | 53.79 | 5.8 | 124 | 42 | 86 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 7°C | −3°C | 2.1°C | 101 mm | 5 cm |
| February | 10°C | −1°C | 4.1°C | 118 mm | 4 cm |
| March | 15°C | 3°C | 8.9°C | 133 mm | 3 cm |
| April | 21°C | 8°C | 14.4°C | 133 mm | 0 cm |
| May | 26°C | 14°C | 19.8°C | 141 mm | 0 cm |
| June | 30°C | 19°C | 24.3°C | 112 mm | 0 cm |
| July | 31°C | 20°C | 25.8°C | 103 mm | 0 cm |
| August | 31°C | 19°C | 24.9°C | 85 mm | 0 cm |
| September | 28°C | 15°C | 21.3°C | 97 mm | 0 cm |
| October | 22°C | 8°C | 14.9°C | 101 mm | 0 cm |
| November | 15°C | 2°C | 8.6°C | 113 mm | 1 cm |
| December | 9°C | −1°C | 3.9°C | 131 mm | 2 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00409219; 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 City?
Normal highs sit between 65°F and 85°F in April, May, September and October. Of those, September has the fewest days with rain (8).
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 USC00409219.
When is the last frost in Union City?
In Union City, the last spring frost (32°F) comes after April 3 in half of years and after April 19 in one year in ten; the first autumn frost comes before October 29 in half of years and before October 17 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 31 year in 10 after April 19; 9 in 10 after March 18
- First autumn frost, half of years before
- October 291 year in 10 before October 17; 9 in 10 before November 10
NOAA puts the median frost-free season at 208 days, and the season without a hard freeze (28°F) at 230 days.
A hard freeze (28°F) comes after March 22 in half of springs and before November 7 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Union City in zone 7b in ZIP code 38261, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Union City's NOAA station is in zone 7b: the coldest night of a typical year reaches 7°F (29 complete years).
Frost dates for every NOAA station in Tennessee · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00409219; 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 City?
In a normal year in Union City, 42 days a year reach 90°F (1 of them 100°F or more), 86 nights fall to 32°F or colder and 124 days bring measurable precipitation.
- Days at 90°F or more
- 42a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 86a normal year
- Days that stay below freezing
- 11high of 32°F or less
- Days with 0.01 inch of precipitation
- 124a normal year
- Days with 1 inch of snow or more
- 2a normal year
The highest temperature in this station's record (since 1895) is 111°F, on August 10, 1930; the lowest is −22°F, on January 9, 1942.
The wettest calendar year on that record is 1957, with 80.19 in; the snowiest season is 1977–78, with 34.3 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00409219; records: ACIS (NOAA Regional Climate Centers), station USC00409219. Records use complete months only; a month missing more than three days is left out.
How sunny is Union City?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Union City, 4.4 kWh per square metre a day. August is the sunniest month (84%) and February the cloudiest (65%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 68% | 2.3 |
| February | 65% | 2.9 |
| March | 69% | 4.0 |
| April | 75% | 5.3 |
| May | 76% | 5.9 |
| June | 82% | 6.6 |
| July | 84% | 6.4 |
| August | 84% | 5.8 |
| September | 82% | 4.9 |
| October | 77% | 3.7 |
| November | 73% | 2.6 |
| December | 67% | 2.0 |
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 City need?
A normal year in Union City brings 4,060 heating degree days, 24% fewer than the median U.S. place (5,373), and 1,526 cooling degree days, 68% more than the median (908). Five months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 4,461 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 908 | 0 |
| February | 717 | 0 |
| March | 532 | 5 |
| April | 243 | 30 |
| May | 60 | 144 |
| June | 2 | 326 |
| July | 0 | 418 |
| August | 1 | 369 |
| September | 31 | 190 |
| October | 230 | 40 |
| November | 531 | 3 |
| December | 806 | 0 |
| Year (annual) | 4,060 | 1,526 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00409219. 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.
Has Union City been warmer than normal lately?
2023 averaged 60.2°F, 2.3°F above the 1991-2020 normal of 57.9°F. 2 of the 3 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 58.3°F | +0.4°F | 54.97 | 8.3 |
| 2022 | 57.3°F | −0.6°F | 53.22 | 8.9 |
| 2023 | 60.2°F | +2.3°F | 58.03 | 0.0 |
Over 79 complete years from 1896 to 2023, the station's annual mean temperature rose at a fitted -1.5°F per century (−0.08°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00409219; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Union City's climate compare?
Union City is warmer than 40 of the other 115 places with their own NOAA record in Tennessee, and wetter than 26. Across the 7,247 U.S. stations with normals, its annual mean of 57.9°F is warmer than 69%.
In the Köppen classification computed from these normals, Union City 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.
Which places near Union City share this climate record?
7 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.
- Troy, TN1,407 people · 8 mi SW
- Clinton, KY1,180 people · 19 mi N
- Obion, TN968 people · 13 mi SW
- Trimble, TN532 people · 16 mi SW
- Woodland Mills, TN338 people · 7 mi NW
- Rives, TN246 people · 3 mi S
- Cayce, KY74 people · 11 mi N
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 Union City's climate
What is the coldest month in Union City?
January, with a normal high of 45°F and a normal low of 27°F. The warmest is July (88°F by day, 69°F at night).
Does it snow in Union City?
Yes: 6 inches in a normal year, falling on 4 days with 0.1 inch or more, the most in January (2.1 inches).
What is the rainiest month in Union City?
May, with 5.56 in of precipitation in a normal year; the driest is August with 3.34 in.
What plant hardiness zone is Union City in?
The USDA's 2023 map puts Union City in zone 7b in ZIP code 38261, the nearest ZIP area. By the same method at Union City's NOAA station, the coldest night of a typical year reaches 7°F (29 years, 1991-2020): zone 7b.
How late can frost come in Union City?
In half of years the last 32°F night comes after April 3; in one year in ten it comes after April 19. Waiting until April 19 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Tennessee climateThe statewide normals and every place in the state
- Martin, TN10 miles from this station, 58.9°F a year
- Samburg, TN16 miles from this station, 57.8°F a year
- Dresden, TN20 miles from this station, 58.6°F a year
- New Madrid, MO31 miles from this station, 58.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made