Weather in Phoenix in December

Prime time. December is about as good as Phoenix gets. Highs average 19.7 °C, lows 6.3 °C, and rain falls on 4 days — nothing in the month is working against you.

December ranks 5 of 12 in Phoenix: past the worst of the year but short of November, which is the month to book if the dates are open.

Rain falls on only 4 days, so an itinerary with no wet-weather fallback is a reasonable risk. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

Averages flatten a month, and this one hides a few things: it never really gets hot: not one day in an average December reaches 30 °C. Across the twenty years measured, the hottest December day reached 29.5 °C and the coldest night fell to -2.9 °C, and the wettest single day dropped 27 mm — roughly 87% of the month's rain in one day.

December is moderately variable: 0 mm in the driest year against 67 mm in the wettest, around an average of 31 mm. Roughly two Decembers in three land near that average, and the third does something else entirely.

Wind is light at 6.5 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 45%.

How December sits in the year

Temperatures hold steady either side: 25.9 °C in November, 19.7 here, 20.4 in January. Nothing about the timing within the month matters much.

Daylight in December

December sits at the dark end of Phoenix's year — 10 hours of daylight against 14.4 at midsummer, holding steady all month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

An inland climate

With no coast nearby, the year swings a fair way — 35.6 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

December in Phoenix versus nearby

If Phoenix is one option among several, the nearby comparison is worth making. Sedona is the weaker option in December — 8.1 °C cooler, 2 days more rain. Tucson is close enough to be a coin toss — within a degree on temperature, 1 day more rain.

So: December is effectively as good as it gets here — 6 points behind November, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in Phoenix

See all twelve months in Phoenix, or where else to go in December.