Portland weather in December: Portland, Maine: normal highs, lows, rain and records for December
Portland in December has a normal high of 38°F and a normal low of 22°F, a daily mean of 30°F, falling from 43°F on the 1st to 34°F by the 31st. Measurable precipitation falls on 12 days in a normal December, 4.50 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 3°C and low of −5°C, 114 mm of precipitation and 37 cm of snow in December.
- NOAA stationPortland International Jetport
- Station IDUSW00014764
- Location43.65°N 70.30°W
- Elevation45 ft (14 m)
- From the center6 miles
- Population69,568
- Jan 32° 16°
- Feb 35° 17°
- Mar 42° 26°
- Apr 54° 35°
- May 64° 46°
- Jun 74° 55°
- Jul 80° 61°
- Aug 79° 60°
- Sep 71° 52°
- Oct 60° 41°
- Nov 48° 32°
- Dec 38° 22°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Portland in December?
The normal high is 38°F and the normal low 22°F, for a daily mean of 30.3°F. December is 9.7°F cooler than November and 6.3°F warmer than January. December is the 10th warmest month of the year in Portland and the 2nd wettest. Across the month the normal high falls 9°F, from 43°F on December 1 to 34°F on December 31. From one year to the next December's mean temperature typically moves about 3.5°F either way (NOAA's standard deviation), so roughly two Decembers in three average between 27°F and 34°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 40%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| December 1 | 43°F | 27°F | 38% | 24% |
| December 8 | 41°F | 25°F | 39% | 25% |
| December 15 | 38°F | 23°F | 39% | 25% |
| December 22 | 37°F | 21°F | 40% | 25% |
| December 31 | 34°F | 18°F | 39% | 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 | 43°F | 27°F | 38% | 24% | 9 h 10 min |
| December 2 | 43°F | 27°F | 39% | 24% | 9 h 10 min |
| December 3 | 42°F | 26°F | 39% | 24% | 9 h 10 min |
| December 4 | 42°F | 26°F | 39% | 24% | 9 h 10 min |
| December 5 | 42°F | 26°F | 39% | 24% | 9 h 10 min |
| December 6 | 41°F | 25°F | 39% | 25% | 9 h 10 min |
| December 7 | 41°F | 25°F | 39% | 25% | 9 h |
| December 8 | 41°F | 25°F | 39% | 25% | 9 h |
| December 9 | 40°F | 24°F | 39% | 25% | 9 h |
| December 10 | 40°F | 24°F | 39% | 25% | 9 h |
| December 11 | 40°F | 24°F | 39% | 25% | 9 h |
| December 12 | 39°F | 24°F | 39% | 25% | 9 h |
| December 13 | 39°F | 23°F | 39% | 25% | 9 h |
| December 14 | 39°F | 23°F | 39% | 25% | 9 h |
| December 15 | 38°F | 23°F | 39% | 25% | 9 h |
| December 16 | 38°F | 22°F | 39% | 25% | 9 h |
| December 17 | 38°F | 22°F | 39% | 25% | 9 h |
| December 18 | 38°F | 22°F | 39% | 25% | 9 h |
| December 19 | 37°F | 21°F | 39% | 25% | 9 h |
| December 20 | 37°F | 21°F | 39% | 25% | 9 h |
| December 21 | 37°F | 21°F | 39% | 25% | 9 h |
| December 22 | 37°F | 21°F | 40% | 25% | 9 h |
| December 23 | 36°F | 20°F | 40% | 25% | 9 h |
| December 24 | 36°F | 20°F | 40% | 25% | 9 h |
| December 25 | 36°F | 20°F | 40% | 25% | 9 h |
| December 26 | 36°F | 20°F | 40% | 25% | 9 h |
| December 27 | 35°F | 19°F | 40% | 25% | 9 h |
| December 28 | 35°F | 19°F | 40% | 25% | 9 h |
| December 29 | 35°F | 19°F | 40% | 25% | 9 h |
| December 30 | 35°F | 19°F | 39% | 25% | 9 h |
| December 31 | 34°F | 18°F | 39% | 25% | 9 h |
- Normal high
- 38°FDecember average
- Normal low
- 22°FDecember average
- Precipitation
- 4.50 inmonth total
- Days with precipitation
- 120.01 inch or more
- Snowfall
- 14.6 inmonth total
- Nights at 32°F or colder
- 27
- Daylight
- 9 h 10 min to 9 hDecember 1 to December 31
- Sunshine
- 64%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00014764; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain or snow in Portland in December?
On a given December day the chance of 0.01 inch or more is 39% on average, highest around December 22 (40%). In all, 4.50 in falls on 12 days of a normal December, 1 of them with an inch or more.
In a normal December in Portland, 27 nights fall to freezing, 8 days stay below freezing all day and snowfall averages 14.6 inches.
Snow falls on 6 days in a normal December, and an inch or more covers the ground on 11 days.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00014764.
How humid and windy is Portland in December?
At 3 p.m. the normal temperature is 32°F with 56% relative humidity and a dew point of 18°F; at 6 a.m. it is 23°F with 75% humidity. The wind averages 7.8 mph, most often from the west-northwest in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 23°F | 16°F | 75% | 6.6 mph | 51% |
| 9 a.m. | 25°F | 17°F | 70% | 7.8 mph | 50% |
| noon | 31°F | 18°F | 58% | 9.7 mph | 46% |
| 3 p.m. | 32°F | 18°F | 56% | 9.6 mph | 51% |
| 6 p.m. | 28°F | 17°F | 63% | 7.5 mph | 56% |
| 9 p.m. | 26°F | 17°F | 68% | 7.4 mph | 55% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00014764. 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 Portland?
The warmest December temperature on Portland's official record (since 1874) is 71°F, on December 7, 1998; the coldest is −21°F, on December 30, 1917. The wettest December brought 9.69 in (1969); the snowiest, 54.8 inches (1970).
The December mean against the 1991-2020 normal of 30.3°F: 2021 32.1°F (+1.8), 2022 31.9°F (+1.6), 2023 35.2°F (+4.9), 2024 29.5°F (−0.8), 2025 24.5°F (−5.8). 3 of 5 ran warmer than normal.
| December | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 32.1°F | +1.8°F | 3.76 in |
| 2022 | 31.9°F | +1.6°F | 3.98 in |
| 2023 | 35.2°F | +4.9°F | 6.67 in |
| 2024 | 29.5°F | −0.8°F | 5.18 in |
| 2025 | 24.5°F | −5.8°F | 3.97 in |
Source: records: ACIS, NWS threaded record PWMthr; recent months: ACIS, station USW00014764. Records and recent months use complete months only.
How does December in Portland compare across Maine?
Across the 42 places PlainClimate covers in Maine, December normal highs run from 26°F in Fort Kent to 39°F in Kennebunkport; Portland's is 38°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.