Phoenix weather in December
In December, Phoenix has an average high of 19 °C66 °F and an average low of 5 °C42 °F, with about 31 mm1.2 in of precipitation. December is the coldest month of the year and ranks 5th for precipitation.
How December compares with other months
Compared with November, December is 5.8 °C10.5 °F cooler on average and wetter by 12 mm0.5 in. Compared with January, December is about the same temperature. Daylight lasts about 9.9 hours around the middle of the month. Average relative humidity is 45% and the average cloud amount 41%.
Is December a good time to visit Phoenix?
Yes — December is one of the most comfortable months to visit Phoenix by our comfort score, which favours average highs of 21–28 °C, lows above 5 °C, little rain and moderate humidity.
What to wear in December
For Phoenix in December, pack light layers — T-shirts plus a light sweater or jacket and an extra layer for the cooler mornings and evenings.
December in nearby places
| Place | High °C°F | Low °C°F | Precip. mmin |
|---|---|---|---|
| Phoenix | 1966 | 542 | 311.2 |
| Peoria | 1865 | 541 | 210.8 |
| Mesa | 1865 | 541 | 311.2 |
| Tucson | 1864 | 439 | 251.0 |
| Yuma | 1967 | 643 | 100.4 |
| Nogales | 1660 | 235 | 251.0 |
| San Luis Río Colorado | 1967 | 642 | 100.4 |
| Mexicali | 2068 | 745 | 210.8 |
| Henderson | 1457 | 236 | 180.7 |
Nearby places that are more than 1 °C1.8 °F warmer in December: Mexicali; cooler: Tucson, Nogales and Henderson.
Other months in Phoenix
- January19 °C67 °F / 6 °C42 °F
- February21 °C70 °F / 7 °C44 °F
- March26 °C78 °F / 10 °C50 °F
- April30 °C86 °F / 13 °C56 °F
- May35 °C96 °F / 18 °C65 °F
- June42 °C107 °F / 24 °C76 °F
- July42 °C107 °F / 28 °C83 °F
- August41 °C105 °F / 27 °C81 °F
- September38 °C101 °F / 24 °C75 °F
- October32 °C90 °F / 17 °C63 °F
- November25 °C77 °F / 11 °C51 °F
- December19 °C66 °F / 5 °C42 °F
Frequently asked questions
How warm is Phoenix in December?
In December the average high in Phoenix is 19 °C (66 °F) and the average low is 5 °C (42 °F).
Does it rain a lot in Phoenix in December?
On average about 31 mm (1.2 in) of precipitation falls in December; it ranks 5th of the 12 months.
Is December the warmest month in Phoenix?
No. The warmest month in Phoenix is July, with an average high of 42 °C (107 °F). The coldest month is December, with an average low of 5 °C (42 °F).
How long is the day in Phoenix in December?
In the middle of December the day in Phoenix lasts about 9.9 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Phoenix in December?
The average relative humidity in December is about 45%. This is a long-term average for the whole day.
How cloudy is Phoenix in December?
On average about 41% of the sky is covered by cloud in December. This is the mean cloud amount from satellite data, not the number of sunny days.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 494 m, while Phoenix lies at about 331 m. Temperatures on this page were therefore adjusted by +1.1 °C1.9 °F using the standard lapse rate of 6.5 °C per 1,000 m.