Phoenix Weather in December

December has the coolest and cloudiest weather of the year for Phoenix. In this southern Arizona city that means pleasantly mild temperatures and mostly sunny skies.

This page gives detailed information on the typical December temperature, precipitation, sun, humidity, wind and storms for Phoenix. The weather measurements are averages based on climate data gathered at Phoenix Sky Harbor International Airport, located near the city center.

Temperature

66 °F	December average high	19 °C
45 °F	December average low	7 °C

December is the coldest month overall for Phoenix and the 20th to 27th are its chilliest days. They have daily highs averaging 65 degrees Fahrenheit (18 degrees Celsius) and lows of 44 °F (7 °C).

11 days	70 °F max. or more (21 °C)
26 days	50 °F min. or less (10 °C)

Nearly every December day warms to over 60 °F (16 °C) in Phoenix. Temperatures in December above 80 °F (27 °C) happen once every few years.

The thermometer dips to 40 °F (4 °C) or below on 7 nights. December averages just one night a decade when the temperature drops to freezing.

Rain

0.7 in	total precipitation	19 mm
4 days	of rain

Half the time, Phoenix receives 0.2 to 1.0 inches (5 to 25 mm) of rainfall in December. One in four years has drier weather, while another one in four is wetter.

Sun

77 %	sunshine
15 days	clear skies

December is the cloudiest month for Phoenix. The sun's rays reach the ground during 77 percent of daylight hours on average, for a total of 238 hours in the month. Typically on 15 days this month the sky is mainly clear, with at most 30 percent cloud cover.

Sunlight in December at Phoenix averages 9 hours and 58 minutes a day. The shortest days of the year, from around December 17th to 24th, last 9 hours and 56 minutes from sunrise to sunset.

Humidity

52 %	December average humidity

The relative humidity in Phoenix during December usually peaks at 67 percent in the morning then drops to 33 percent by late afternoon. December is the most humid month for Phoenix.

Local Time	2 am	5 am	8 am	11 am	2 pm	5 pm	8 pm	11 pm
Humidity %	63	66	67	46	34	33	48	57

Wind

5.1 mph

December wind speed average

8.2 kph

The wind at Phoenix is calmest overall during December.

Storms

0 days	rainfall of 0.5 inches (13 mm) or more
1 day	with thunderstorms in December

December is the month that Phoenix is most likely to receive an inch (25 mm) or more of rain in one day. Most years, though, Phoenix doesn't see rain that heavy in December.

Phoenix averages one December thunderstorm every two years.