Johnstown weather in December: Johnstown, Pennsylvania: normal highs, lows, rain and records for December
Johnstown in December has a normal high of 38°F and a normal low of 25°F, a daily mean of 31°F, falling from 42°F on the 1st to 35°F by the 31st. Measurable precipitation falls on 15 days in a normal December, 2.68 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 3°C and low of −4°C, 68 mm of precipitation in December.
- NOAA stationJohnstown Cambria County Airport
- Station IDUSW00004726
- Location40.32°N 78.83°W
- Elevation2,284 ft (696 m)
- From the center5 miles
- Population17,853
- Jan 33° 19°
- Feb 36° 21°
- Mar 45° 28°
- Apr 58° 38°
- May 68° 49°
- Jun 75° 57°
- Jul 79° 61°
- Aug 77° 60°
- Sep 71° 53°
- Oct 59° 43°
- Nov 47° 33°
- Dec 38° 25°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Johnstown in December?
The normal high is 38°F and the normal low 25°F, for a daily mean of 31.2°F. December is 8.9°F cooler than November and 4.9°F warmer than January. December is the 10th warmest month of the year in Johnstown and the 10th wettest. Across the month the normal high falls 7°F, from 42°F on December 1 to 35°F on December 31. From one year to the next December's mean temperature typically moves about 4.7°F either way (NOAA's standard deviation), so roughly two Decembers in three average between 27°F and 36°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 48%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| December 1 | 42°F | 28°F | 47% | 23% |
| December 8 | 40°F | 26°F | 47% | 23% |
| December 15 | 38°F | 25°F | 47% | 23% |
| December 22 | 36°F | 23°F | 48% | 23% |
| December 31 | 35°F | 21°F | 48% | 22% |
Every day of December: normal high, low and chance of precipitation (warmest afternoon December 1, coldest night December 31)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| December 1 | 42°F | 28°F | 47% | 23% | 9 h 30 min |
| December 2 | 41°F | 28°F | 47% | 23% | 9 h 30 min |
| December 3 | 41°F | 28°F | 47% | 23% | 9 h 30 min |
| December 4 | 41°F | 27°F | 47% | 23% | 9 h 30 min |
| December 5 | 41°F | 27°F | 47% | 23% | 9 h 30 min |
| December 6 | 40°F | 27°F | 47% | 23% | 9 h 30 min |
| December 7 | 40°F | 27°F | 47% | 23% | 9 h 30 min |
| December 8 | 40°F | 26°F | 47% | 23% | 9 h 20 min |
| December 9 | 39°F | 26°F | 47% | 23% | 9 h 20 min |
| December 10 | 39°F | 26°F | 47% | 23% | 9 h 20 min |
| December 11 | 39°F | 26°F | 47% | 23% | 9 h 20 min |
| December 12 | 39°F | 26°F | 47% | 23% | 9 h 20 min |
| December 13 | 38°F | 25°F | 47% | 23% | 9 h 20 min |
| December 14 | 38°F | 25°F | 47% | 23% | 9 h 20 min |
| December 15 | 38°F | 25°F | 47% | 23% | 9 h 20 min |
| December 16 | 38°F | 25°F | 47% | 23% | 9 h 20 min |
| December 17 | 37°F | 24°F | 48% | 23% | 9 h 20 min |
| December 18 | 37°F | 24°F | 48% | 23% | 9 h 20 min |
| December 19 | 37°F | 24°F | 48% | 23% | 9 h 20 min |
| December 20 | 37°F | 24°F | 48% | 23% | 9 h 20 min |
| December 21 | 37°F | 23°F | 48% | 23% | 9 h 20 min |
| December 22 | 36°F | 23°F | 48% | 23% | 9 h 20 min |
| December 23 | 36°F | 23°F | 48% | 22% | 9 h 20 min |
| December 24 | 36°F | 23°F | 48% | 22% | 9 h 20 min |
| December 25 | 36°F | 23°F | 48% | 22% | 9 h 20 min |
| December 26 | 36°F | 22°F | 48% | 22% | 9 h 20 min |
| December 27 | 35°F | 22°F | 48% | 22% | 9 h 20 min |
| December 28 | 35°F | 22°F | 48% | 22% | 9 h 20 min |
| December 29 | 35°F | 22°F | 48% | 22% | 9 h 20 min |
| December 30 | 35°F | 21°F | 48% | 22% | 9 h 20 min |
| December 31 | 35°F | 21°F | 48% | 22% | 9 h 20 min |
- Normal high
- 38°FDecember average
- Normal low
- 25°FDecember average
- Precipitation
- 2.68 inmonth total
- Days with precipitation
- 150.01 inch or more
- Nights at 32°F or colder
- 25
- Daylight
- 9 h 30 min to 9 h 20 minDecember 1 to December 31
- Sunshine
- 53%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00004726; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Johnstown in December?
On a given December day the chance of 0.01 inch or more is 47% on average, highest around December 31 (48%). In all, 2.68 in falls on 15 days of a normal December.
In a normal December in Johnstown, 25 nights fall to freezing and 12 days stay below freezing all day.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00004726.
How humid and windy is Johnstown in December?
At 3 p.m. the normal temperature is 31°F with 69% relative humidity and a dew point of 22°F; at 6 a.m. it is 27°F with 80% humidity. The wind averages 11.4 mph, most often from the west in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 27°F | 21°F | 80% | 11.2 mph | – |
| 9 a.m. | 27°F | 21°F | 79% | 11.4 mph | – |
| noon | 30°F | 23°F | 74% | 12.3 mph | – |
| 3 p.m. | 31°F | 22°F | 69% | 12.1 mph | – |
| 6 p.m. | 29°F | 22°F | 73% | 10.7 mph | – |
| 9 p.m. | 28°F | 21°F | 76% | 11.4 mph | – |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00004726. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for December in Johnstown?
The warmest December temperature on this station's record (since 2000) is 71°F, on December 5, 2001; the coldest is −8°F, on December 24, 2022. The wettest December brought 6.48 in (2008).
The December mean against the 1991-2020 normal of 31.2°F: 2021 38.8°F (+7.6), 2022 30.5°F (−0.7), 2023 37.9°F (+6.7), 2024 31.9°F (+0.7), 2025 27.5°F (−3.7). 3 of 5 ran warmer than normal.
| December | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 38.8°F | +7.6°F | 4.08 in |
| 2022 | 30.5°F | −0.7°F | 2.40 in |
| 2023 | 37.9°F | +6.7°F | 2.46 in |
| 2024 | 31.9°F | +0.7°F | 2.90 in |
| 2025 | 27.5°F | −3.7°F | 2.12 in |
Source: records: ACIS, station USW00004726; recent months: ACIS, station USW00004726. Records and recent months use complete months only.
How does December in Johnstown compare across Pennsylvania?
Across the 108 places PlainClimate covers in Pennsylvania, December normal highs run from 34°F in Laporte to 48°F in Marcus Hook; Johnstown's is 38°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Johnstown in November47°F by day, 33°F at night
- Johnstown in January33°F by day, 19°F at night
- Johnstown through the yearEvery month, frost dates, records and recent years
- Pennsylvania in DecemberThe statewide normal and the warmest and coolest places
- Marcus Hook: Pennsylvania's warmest Decembernormal high 48°F