What December feels like in Phoenix
December is early winter in Phoenix, although winter here means mild days rather than cold ones. Afternoons are mild and comfortable for most people in light layers. Temperatures fall sharply after dark — a swing of roughly 12.6°C (22.7°F) — and nights are cold. The air is comfortable — neither muggy nor dry.
Rain in Phoenix in December
Most days stay dry; rain arrives about one day in 8. Each rainy day adds about 8.1 mm (0.3 in), a proper wetting rather than a sprinkle. Across the year Phoenix averages about 8 mm per rainy day, so December is typical. It is among the three wettest months of the year.
Daylight and sunshine in December
On 15 December the sun rises at about 7:25 am and sets around 5:22 pm local time, giving 9 h 57 min of daylight. Days are getting shorter: 30 min less daylight than in mid-November. The sun is out for roughly 84% of those daylight hours, so skies are mostly clear.
How December compares to the rest of the year
Ranked by average high, December comes out as the coolest month in Phoenix. Compared with November, afternoons are 6.3°C (11.3°F) cooler, with 13 mm more rain. The cooling trend carries on into January. The next month's average high: 18.7°C (65.7°F).
Who December suits
- Sightseeing: a good fit — comfortable enough to explore on foot all day.
- Parks & outdoor: a good fit — comfortable for long walks and picnics.
Tips for visiting Phoenix in December
Versatile Layers
Mornings and evenings are cooler than midday, so dress in layers.
Sunglasses
Plenty of sun, so bring sunglasses and a cap.
Quick questions
How warm is Phoenix in December?
Expect around 18.4°C (65.1°F) in the afternoon and 5.8°C (42.4°F) at night, which most visitors would call mild.
Does it rain a lot in Phoenix in December?
Only moderately: roughly 4 wet days and 32 mm, usually moderate rain.
What should I wear in Phoenix in December?
Based on the averages: versatile layers and sunglasses. Bring something extra for the cooler evenings.
Is December or January better for visiting Phoenix?
On our 12-month climate ranking, January comes out ahead (#4 of 12 vs #5). January has fewer rainy days.