Union City, Pennsylvania climate: Normal weather by month, frost dates and records
Union City's normal year runs from 16°F January nights to 80°F July afternoons, with 49.0 inches of precipitation and 114 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.4°C, January lows of −9°C, July highs of 27°C, 1,245 mm of precipitation a year.
- NOAA stationUnion City Filtration Plant
- Station IDUSC00369042
- Location41.90°N 79.86°W
- Elevation1,400 ft (427 m)
- From the centerunder 1 mile
- Population2,857
On October 14, the normal high in Union City is 62°F and the normal low 39°F, and the chance of measurable rain or snow is 47%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Union City.
- Jan 32° 16°
- Feb 35° 15°
- Mar 43° 23°
- Apr 56° 34°
- May 68° 45°
- Jun 76° 54°
- Jul 80° 58°
- Aug 79° 57°
- Sep 73° 49°
- Oct 61° 38°
- Nov 48° 31°
- Dec 37° 23°
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 80°F; January the coldest, with normal lows of 16°F. The most precipitation falls in July (4.72 in), the least in February (2.93 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 32°F | 16°F | 24.3°F | 4.06 | 30.3 | 21 | <1 | 29 | 9 h 30 min |
| February | 35°F | 15°F | 24.8°F | 2.93 | 21.3 | 16 | <1 | 26 | 10 h 30 min |
| March | 43°F | 23°F | 33.1°F | 3.62 | 15.8 | 15 | <1 | 26 | 11 h 50 min |
| April | 56°F | 34°F | 45.1°F | 4.19 | 3.8 | 15 | <1 | 15 | 13 h 20 min |
| May | 68°F | 45°F | 56.4°F | 4.36 | 0.0 | 13 | <1 | 3 | 14 h 30 min |
| June | 76°F | 54°F | 65.0°F | 4.47 | 0.0 | 13 | <1 | <1 | 15 h 10 min |
| July | 80°F | 58°F | 69.2°F | 4.72 | 0.0 | 13 | 1 | <1 | 15 h |
| August | 79°F | 57°F | 67.6°F | 3.72 | 0.0 | 12 | <1 | <1 | 14 h |
| September | 73°F | 49°F | 61.0°F | 4.36 | 0.0 | 12 | <1 | <1 | 12 h 30 min |
| October | 61°F | 38°F | 49.7°F | 4.52 | 0.9 | 15 | <1 | 6 | 11 h 10 min |
| November | 48°F | 31°F | 39.5°F | 3.87 | 14.5 | 16 | <1 | 20 | 9 h 50 min |
| December | 37°F | 23°F | 29.9°F | 4.20 | 27.6 | 18 | <1 | 26 | 9 h 10 min |
| Year (annual) | 57°F | 37°F | 47.1°F | 49.02 | 114.2 | 178 | 1 | 150 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −9°C | −4.3°C | 103 mm | 77 cm |
| February | 1°C | −9°C | −4.0°C | 74 mm | 54 cm |
| March | 6°C | −5°C | 0.6°C | 92 mm | 40 cm |
| April | 14°C | 1°C | 7.3°C | 106 mm | 10 cm |
| May | 20°C | 7°C | 13.6°C | 111 mm | 0 cm |
| June | 24°C | 12°C | 18.3°C | 114 mm | 0 cm |
| July | 27°C | 15°C | 20.7°C | 120 mm | 0 cm |
| August | 26°C | 14°C | 19.8°C | 94 mm | 0 cm |
| September | 23°C | 10°C | 16.1°C | 111 mm | 0 cm |
| October | 16°C | 4°C | 9.8°C | 115 mm | 2 cm |
| November | 9°C | −1°C | 4.2°C | 98 mm | 37 cm |
| December | 3°C | −5°C | −1.2°C | 107 mm | 70 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00369042; 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 May, June, July, August and September. Of those, September has the fewest days with rain (12).
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 USC00369042.
When is the last frost in Union City?
In Union City, the last spring frost (32°F) comes after May 7 in half of years and after May 24 in one year in ten; the first autumn frost comes before October 10 in half of years and before September 29 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
- May 71 year in 10 after May 24; 9 in 10 after April 23
- First autumn frost, half of years before
- October 101 year in 10 before September 29; 9 in 10 before October 24
NOAA puts the median frost-free season at 155 days, and the season without a hard freeze (28°F) at 181 days.
A hard freeze (28°F) comes after April 24 in half of springs and before October 23 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Union City in zone 6a in ZIP code 16438, the nearest ZIP area.
Frost dates for every NOAA station in Pennsylvania · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00369042; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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, 1 day a year reaches 90°F, 150 nights fall to 32°F or colder and 178 days bring measurable precipitation.
- Days at 90°F or more
- 1a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 150a normal year
- Days that stay below freezing
- 48high of 32°F or less
- Days with 0.01 inch of precipitation
- 178a normal year
- Days with 1 inch of snow or more
- 35a normal year
Source: NOAA NCEI 1991-2020 annual normals, station USC00369042.
How sunny is Union City?
Over a year 67% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Union City, 3.6 kWh per square metre a day. August is the sunniest month (76%) and December the cloudiest (47%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 52% | 1.5 |
| February | 56% | 2.2 |
| March | 59% | 3.3 |
| April | 65% | 4.5 |
| May | 68% | 5.3 |
| June | 73% | 5.9 |
| July | 76% | 5.9 |
| August | 76% | 5.2 |
| September | 73% | 4.2 |
| October | 63% | 2.7 |
| November | 60% | 1.8 |
| December | 47% | 1.1 |
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 6,901 heating degree days, 28% more than the median U.S. place (5,373), and 420 cooling degree days, 54% 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 2,350 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,261 | 0 |
| February | 1,127 | 0 |
| March | 989 | 0 |
| April | 598 | 1 |
| May | 290 | 23 |
| June | 75 | 74 |
| July | 24 | 153 |
| August | 40 | 121 |
| September | 166 | 46 |
| October | 478 | 4 |
| November | 765 | 0 |
| December | 1,088 | 0 |
| Year (annual) | 6,901 | 420 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00369042. 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?
2025 averaged 46.9°F, 0.3°F below the 1991-2020 normal of 47.1°F. 3 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 49.5°F | +2.4°F | 47.15 | 61.0 |
| 2023 | 48.8°F | +1.7°F | 43.89 | 59.9 |
| 2024 | 49.7°F | +2.6°F | 47.14 | 72.1 |
| 2025 | 46.9°F | −0.3°F | 47.56 | 132.9 |
Source: observed years: ACIS, station USC00369042. A year counts only with all twelve months complete.
How does Union City's climate compare?
Union City is warmer than 16 of the other 107 places with their own NOAA record in Pennsylvania, and wetter than 91. Across the 7,247 U.S. stations with normals, its annual mean of 47.1°F is warmer than 28%.
In the Köppen classification computed from these normals, Union City is Dfb: continental, 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 Union City share this climate record?
13 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.
- Corry, PA6,065 people · 12 mi E
- Edinboro, PA5,814 people · 14 mi W
- Cambridge Springs, PA2,333 people · 12 mi SW
- Waterford, PA1,445 people · 7 mi NW
- Columbus, PA721 people · 15 mi E
- Mill Village, PA384 people · 6 mi W
- Canadohta Lake, PA365 people · 6 mi S
- Wattsburg, PA343 people · 8 mi N
- Spartansburg, PA275 people · 11 mi SE
- Elgin, PA199 people · 6 mi E
- Rockdale Acres, PA116 people · 10 mi S
- Lincolnville, PA84 people · 8 mi S
- Riceville, PA76 people · 9 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 Union City's climate
What is the coldest month in Union City?
January, with a normal high of 32°F and a normal low of 16°F. The warmest is July (80°F by day, 58°F at night).
Does it snow in Union City?
Yes: 114 inches in a normal year, falling on 53 days with 0.1 inch or more, the most in January (30.3 inches).
What is the rainiest month in Union City?
July, with 4.72 in of precipitation in a normal year; the driest is February with 2.93 in.
What plant hardiness zone is Union City in?
The USDA's 2023 map puts Union City in zone 6a in ZIP code 16438, the nearest ZIP area.
How late can frost come in Union City?
In half of years the last 32°F night comes after May 7; in one year in ten it comes after May 24. Waiting until May 24 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Pennsylvania climateThe statewide normals and every place in the state
- Titusville, PA21 miles from this station, 46.9°F a year
- Erie, PA21 miles from this station, 50.8°F a year
- Port Meadville Airport, PA26 miles from this station, 48.6°F a year
- Chandlers Valley (1 mi SE), PA29 miles from this station, 45.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made