Rockville weather in December: Rockville, Maryland: normal highs, lows, rain and records for December
Rockville in December has a normal high of 46°F and a normal low of 31°F, a daily mean of 39°F, falling from 50°F on the 1st to 43°F by the 31st. Measurable precipitation falls on 9 days in a normal December, 3.38 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 8°C and low of −1°C, 86 mm of precipitation in December.
- NOAA stationRockville (1 mi NE)
- Station IDUSC00187705
- Location39.10°N 77.15°W
- Elevation440 ft (134 m)
- From the center1 miles
- Population68,417
- Jan 42° 27°
- Feb 45° 28°
- Mar 54° 36°
- Apr 66° 46°
- May 74° 55°
- Jun 82° 64°
- Jul 87° 69°
- Aug 85° 67°
- Sep 78° 60°
- Oct 66° 48°
- Nov 56° 38°
- Dec 46° 31°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Rockville in December?
The normal high is 46°F and the normal low 31°F, for a daily mean of 38.5°F. December is 8.4°F cooler than November and 4.0°F warmer than January. December is the 10th warmest month of the year in Rockville and the 7th wettest. Across the month the normal high falls 7°F, from 50°F on December 1 to 43°F on December 31. From one year to the next December's mean temperature typically moves about 3.9°F either way (NOAA's standard deviation), so roughly two Decembers in three average between 35°F and 42°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 32%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| December 1 | 50°F | 34°F | 31% | 19% |
| December 8 | 48°F | 32°F | 32% | 19% |
| December 15 | 46°F | 31°F | 32% | 20% |
| December 22 | 44°F | 30°F | 32% | 19% |
| December 31 | 43°F | 28°F | 32% | 19% |
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 | 50°F | 34°F | 31% | 19% | 9 h 40 min |
| December 2 | 50°F | 34°F | 31% | 19% | 9 h 40 min |
| December 3 | 49°F | 33°F | 31% | 19% | 9 h 40 min |
| December 4 | 49°F | 33°F | 31% | 19% | 9 h 40 min |
| December 5 | 49°F | 33°F | 31% | 19% | 9 h 30 min |
| December 6 | 49°F | 33°F | 31% | 19% | 9 h 30 min |
| December 7 | 48°F | 33°F | 32% | 19% | 9 h 30 min |
| December 8 | 48°F | 32°F | 32% | 19% | 9 h 30 min |
| December 9 | 48°F | 32°F | 32% | 20% | 9 h 30 min |
| December 10 | 47°F | 32°F | 32% | 20% | 9 h 30 min |
| December 11 | 47°F | 32°F | 32% | 20% | 9 h 30 min |
| December 12 | 47°F | 32°F | 32% | 20% | 9 h 30 min |
| December 13 | 46°F | 31°F | 32% | 20% | 9 h 30 min |
| December 14 | 46°F | 31°F | 32% | 20% | 9 h 30 min |
| December 15 | 46°F | 31°F | 32% | 20% | 9 h 30 min |
| December 16 | 46°F | 31°F | 32% | 20% | 9 h 30 min |
| December 17 | 45°F | 31°F | 32% | 20% | 9 h 30 min |
| December 18 | 45°F | 30°F | 32% | 20% | 9 h 30 min |
| December 19 | 45°F | 30°F | 32% | 20% | 9 h 30 min |
| December 20 | 45°F | 30°F | 32% | 20% | 9 h 30 min |
| December 21 | 45°F | 30°F | 32% | 19% | 9 h 30 min |
| December 22 | 44°F | 30°F | 32% | 19% | 9 h 30 min |
| December 23 | 44°F | 30°F | 32% | 19% | 9 h 30 min |
| December 24 | 44°F | 29°F | 32% | 19% | 9 h 30 min |
| December 25 | 44°F | 29°F | 32% | 19% | 9 h 30 min |
| December 26 | 44°F | 29°F | 32% | 19% | 9 h 30 min |
| December 27 | 44°F | 29°F | 32% | 19% | 9 h 30 min |
| December 28 | 43°F | 29°F | 32% | 19% | 9 h 30 min |
| December 29 | 43°F | 29°F | 32% | 19% | 9 h 30 min |
| December 30 | 43°F | 29°F | 32% | 19% | 9 h 30 min |
| December 31 | 43°F | 28°F | 32% | 19% | 9 h 30 min |
- Normal high
- 46°FDecember average
- Normal low
- 31°FDecember average
- Precipitation
- 3.38 inmonth total
- Days with precipitation
- 90.01 inch or more
- Nights at 32°F or colder
- 20
- Daylight
- 9 h 40 min to 9 h 30 minDecember 1 to December 31
- Days at 70°F or more
- 1
- Sunshine
- 66%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00187705; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Rockville in December?
On a given December day the chance of 0.01 inch or more is 32% on average, highest around December 13 (32%). In all, 3.38 in falls on 9 days of a normal December, 1 of them with an inch or more.
In a normal December in Rockville, 20 nights fall to freezing and 3 days stay below freezing all day.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00187705.
What are the records for December in Rockville?
The warmest December temperature on this station's record (since 1907) is 80°F, on December 29, 1984; the coldest is −12°F, on December 27, 1914. The wettest December brought 6.39 in (1972); the snowiest, 20.0 inches (1962).
Source: records: ACIS, station USC00187705. Records and recent months use complete months only.
How does December in Rockville compare across Maryland?
Across the 26 places PlainClimate covers in Maryland, December normal highs run from 38°F in Frostburg to 52°F in Snow Hill; Rockville's is 46°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.