Norristown weather in December: Norristown, Pennsylvania: normal highs, lows, rain and records for December
Norristown in December has a normal high of 46°F and a normal low of 28°F, a daily mean of 37°F, falling from 51°F on the 1st to 43°F by the 31st. Measurable precipitation falls on 11 days in a normal December, 4.73 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 8°C and low of −2°C, 120 mm of precipitation and 11 cm of snow in December.
- NOAA stationNorristown
- Station IDUSC00366370
- Location40.11°N 75.34°W
- Elevation62 ft (19 m)
- From the centerunder 1 mile
- Population36,075
- Jan 42° 23°
- Feb 44° 25°
- Mar 52° 32°
- Apr 65° 42°
- May 75° 52°
- Jun 84° 62°
- Jul 89° 67°
- Aug 87° 65°
- Sep 80° 58°
- Oct 68° 45°
- Nov 57° 35°
- Dec 46° 28°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Norristown in December?
The normal high is 46°F and the normal low 28°F, for a daily mean of 37.3°F. December is 8.6°F cooler than November and 5.2°F warmer than January. December is the 10th warmest month of the year in Norristown and the 3rd wettest. Across the month the normal high falls 8°F, from 51°F on December 1 to 43°F on December 31. From one year to the next December's mean temperature typically moves about 4.0°F either way (NOAA's standard deviation), so roughly two Decembers in three average between 33°F and 41°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 35%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| December 1 | 51°F | 32°F | 33% | 24% |
| December 8 | 48°F | 30°F | 34% | 25% |
| December 15 | 46°F | 29°F | 34% | 26% |
| December 22 | 45°F | 27°F | 35% | 26% |
| December 31 | 43°F | 25°F | 35% | 25% |
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 | 51°F | 32°F | 33% | 24% | 9 h 30 min |
| December 2 | 50°F | 31°F | 34% | 24% | 9 h 30 min |
| December 3 | 50°F | 31°F | 34% | 25% | 9 h 30 min |
| December 4 | 50°F | 31°F | 34% | 25% | 9 h 30 min |
| December 5 | 49°F | 31°F | 34% | 25% | 9 h 30 min |
| December 6 | 49°F | 31°F | 34% | 25% | 9 h 30 min |
| December 7 | 49°F | 30°F | 34% | 25% | 9 h 30 min |
| December 8 | 48°F | 30°F | 34% | 25% | 9 h 30 min |
| December 9 | 48°F | 30°F | 34% | 25% | 9 h 20 min |
| December 10 | 48°F | 30°F | 34% | 25% | 9 h 20 min |
| December 11 | 47°F | 30°F | 34% | 25% | 9 h 20 min |
| December 12 | 47°F | 29°F | 34% | 25% | 9 h 20 min |
| December 13 | 47°F | 29°F | 34% | 25% | 9 h 20 min |
| December 14 | 47°F | 29°F | 34% | 25% | 9 h 20 min |
| December 15 | 46°F | 29°F | 34% | 26% | 9 h 20 min |
| December 16 | 46°F | 28°F | 34% | 26% | 9 h 20 min |
| December 17 | 46°F | 28°F | 35% | 26% | 9 h 20 min |
| December 18 | 46°F | 28°F | 35% | 26% | 9 h 20 min |
| December 19 | 45°F | 28°F | 35% | 26% | 9 h 20 min |
| December 20 | 45°F | 27°F | 35% | 26% | 9 h 20 min |
| December 21 | 45°F | 27°F | 35% | 26% | 9 h 20 min |
| December 22 | 45°F | 27°F | 35% | 26% | 9 h 20 min |
| December 23 | 44°F | 27°F | 35% | 26% | 9 h 20 min |
| December 24 | 44°F | 27°F | 35% | 26% | 9 h 20 min |
| December 25 | 44°F | 26°F | 35% | 26% | 9 h 20 min |
| December 26 | 44°F | 26°F | 35% | 25% | 9 h 20 min |
| December 27 | 44°F | 26°F | 35% | 25% | 9 h 20 min |
| December 28 | 44°F | 26°F | 35% | 25% | 9 h 20 min |
| December 29 | 43°F | 25°F | 35% | 25% | 9 h 20 min |
| December 30 | 43°F | 25°F | 35% | 25% | 9 h 20 min |
| December 31 | 43°F | 25°F | 35% | 25% | 9 h 20 min |
- Normal high
- 46°FDecember average
- Normal low
- 28°FDecember average
- Precipitation
- 4.73 inmonth total
- Days with precipitation
- 110.01 inch or more
- Snowfall
- 4.2 inmonth total
- Nights at 32°F or colder
- 23
- Daylight
- 9 h 30 min to 9 h 20 minDecember 1 to December 31
- Days at 70°F or more
- 1
- Sunshine
- 63%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00366370; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain or snow in Norristown in December?
On a given December day the chance of 0.01 inch or more is 34% on average, highest around December 30 (35%). In all, 4.73 in falls on 11 days of a normal December, 2 of them with an inch or more.
In a normal December in Norristown, 23 nights fall to freezing, 2 days stay below freezing all day and snowfall averages 4.2 inches.
Snow falls on 1 day in a normal December.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00366370.
What are the records for December in Norristown?
The warmest December temperature on this station's record (since 1951) is 76°F, on December 6, 2001; the coldest is −10°F, on December 25, 1983. The wettest December brought 9.03 in (2009); the snowiest, 18.0 inches (2009).
The December mean against the 1991-2020 normal of 37.3°F: 2021 41.5°F (+4.2), 2022 33.5°F (−3.8), 2023 39.7°F (+2.4), 2025 29.9°F (−7.4). 2 of 4 ran warmer than normal.
| December | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 41.5°F | +4.2°F | 1.37 in |
| 2022 | 33.5°F | −3.8°F | 4.46 in |
| 2023 | 39.7°F | +2.4°F | 8.86 in |
| 2025 | 29.9°F | −7.4°F | 3.39 in |
Source: records: ACIS, station USC00366370; recent months: ACIS, station USC00366370. Records and recent months use complete months only.
How does December in Norristown 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; Norristown's is 46°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Norristown in November57°F by day, 35°F at night
- Norristown in January42°F by day, 23°F at night
- Norristown 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