Flagstaff weather in December: Flagstaff, Arizona: normal highs, lows, rain and records for December
Flagstaff in December has a normal high of 43°F and a normal low of 17°F, a daily mean of 30°F, falling from 46°F on the 1st to 42°F by the 31st. Measurable precipitation falls on 7 days in a normal December, 1.90 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 6°C and low of −8°C, 48 mm of precipitation and 47 cm of snow in December.
- NOAA stationFlagstaff Airport
- Station IDUSW00003103
- Location35.14°N 111.67°W
- Elevation7,003 ft (2,135 m)
- Population77,539
- Jan 43° 18°
- Feb 46° 20°
- Mar 52° 24°
- Apr 59° 28°
- May 68° 35°
- Jun 79° 43°
- Jul 82° 51°
- Aug 79° 51°
- Sep 74° 43°
- Oct 64° 32°
- Nov 52° 23°
- Dec 43° 17°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Flagstaff in December?
The normal high is 43°F and the normal low 17°F, for a daily mean of 30.0°F. December is 7.5°F cooler than November and 0.5°F cooler than January. December is the 12th warmest month of the year in Flagstaff and the 5th wettest. Across the month the normal high falls 4°F, from 46°F on December 1 to 42°F on December 31. From one year to the next December's mean temperature typically moves about 2.9°F either way (NOAA's standard deviation), so roughly two Decembers in three average between 27°F and 33°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 23%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| December 1 | 46°F | 19°F | 18% | 12% |
| December 8 | 44°F | 17°F | 20% | 12% |
| December 15 | 43°F | 17°F | 21% | 13% |
| December 22 | 42°F | 16°F | 22% | 13% |
| December 31 | 42°F | 17°F | 23% | 14% |
Every day of December: normal high, low and chance of precipitation (warmest afternoon December 1, coldest night December 18)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| December 1 | 46°F | 19°F | 18% | 12% | 10 h |
| December 2 | 46°F | 19°F | 18% | 12% | 10 h |
| December 3 | 45°F | 18°F | 18% | 12% | 10 h |
| December 4 | 45°F | 18°F | 19% | 12% | 10 h |
| December 5 | 45°F | 18°F | 19% | 12% | 10 h |
| December 6 | 44°F | 18°F | 19% | 12% | 9 h 50 min |
| December 7 | 44°F | 18°F | 19% | 12% | 9 h 50 min |
| December 8 | 44°F | 17°F | 20% | 12% | 9 h 50 min |
| December 9 | 44°F | 17°F | 20% | 12% | 9 h 50 min |
| December 10 | 43°F | 17°F | 20% | 12% | 9 h 50 min |
| December 11 | 43°F | 17°F | 20% | 12% | 9 h 50 min |
| December 12 | 43°F | 17°F | 21% | 13% | 9 h 50 min |
| December 13 | 43°F | 17°F | 21% | 13% | 9 h 50 min |
| December 14 | 43°F | 17°F | 21% | 13% | 9 h 50 min |
| December 15 | 43°F | 17°F | 21% | 13% | 9 h 50 min |
| December 16 | 42°F | 16°F | 22% | 13% | 9 h 50 min |
| December 17 | 42°F | 16°F | 22% | 13% | 9 h 50 min |
| December 18 | 42°F | 16°F | 22% | 13% | 9 h 50 min |
| December 19 | 42°F | 16°F | 22% | 13% | 9 h 50 min |
| December 20 | 42°F | 16°F | 22% | 13% | 9 h 50 min |
| December 21 | 42°F | 16°F | 22% | 13% | 9 h 50 min |
| December 22 | 42°F | 16°F | 22% | 13% | 9 h 50 min |
| December 23 | 42°F | 16°F | 22% | 13% | 9 h 50 min |
| December 24 | 42°F | 16°F | 22% | 13% | 9 h 50 min |
| December 25 | 42°F | 16°F | 22% | 13% | 9 h 50 min |
| December 26 | 42°F | 16°F | 22% | 13% | 9 h 50 min |
| December 27 | 42°F | 16°F | 22% | 14% | 9 h 50 min |
| December 28 | 42°F | 16°F | 22% | 14% | 9 h 50 min |
| December 29 | 42°F | 17°F | 23% | 14% | 9 h 50 min |
| December 30 | 42°F | 17°F | 23% | 14% | 9 h 50 min |
| December 31 | 42°F | 17°F | 23% | 14% | 9 h 50 min |
- Normal high
- 43°FDecember average
- Normal low
- 17°FDecember average
- Precipitation
- 1.90 inmonth total
- Days with precipitation
- 70.01 inch or more
- Snowfall
- 18.5 inmonth total
- Nights at 32°F or colder
- 30
- Daylight
- 10 h to 9 h 50 minDecember 1 to December 31
- Sunshine
- 81%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00003103; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain or snow in Flagstaff in December?
On a given December day the chance of 0.01 inch or more is 21% on average, highest around December 29 (23%). In all, 1.90 in falls on 7 days of a normal December.
In a normal December in Flagstaff, 30 nights fall to freezing, 4 days stay below freezing all day and snowfall averages 18.5 inches.
Snow falls on 6 days in a normal December, and an inch or more covers the ground on 16 days.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00003103.
What are the records for December in Flagstaff?
The warmest December temperature on Flagstaff's official record (since 1898) is 68°F, on December 11, 1950; the coldest is −23°F, on December 8, 1978. The wettest December brought 7.30 in (1967); the snowiest, 86.0 inches (1967).
The December mean against the 1991-2020 normal of 30.0°F: 2021 32.3°F (+2.3), 2022 31.9°F (+1.9), 2023 34.4°F (+4.4), 2024 36.7°F (+6.7), 2025 39.0°F (+9.0). 5 of 5 ran warmer than normal.
| December | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 32.3°F | +2.3°F | 4.54 in |
| 2022 | 31.9°F | +1.9°F | 2.33 in |
| 2023 | 34.4°F | +4.4°F | 0.54 in |
| 2024 | 36.7°F | +6.7°F | 0.00 in |
| 2025 | 39.0°F | +9.0°F | 0.73 in |
Source: records: ACIS, NWS threaded record FLGthr; recent months: ACIS, station USW00003103. Records and recent months use complete months only.
How does December in Flagstaff compare across Arizona?
Across the 97 places PlainClimate covers in Arizona, December normal highs run from 41°F in Lukachukai to 70°F in Gila Bend; Flagstaff's is 43°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.