You’re standing in line at Sky Harbor International Airport. To your left, a guy is wearing a heavy Canada Goose parka. To your right, a teenager is rocking gym shorts and flip-flops.
Both of them look ridiculous.
But honestly? Both of them are also kind of right. Phoenix Arizona weather in December is a weird, beautiful, and sometimes frustrating paradox that confuses the heck out of tourists. One minute you’re sunbathing with a prickly pear margarita, and the next, you’re shivering in a drafty restaurant because the desert floor lost all its heat the second the sun dipped behind the South Mountain.
Most people think "Arizona" and "Desert" equals "Hot." In December, that's a lie. It’s not hot. It’s perfect—until it isn't.
The Reality of the "67-Degree" Average
If you look at the official climate data from the National Weather Service, you’ll see an average high of 67°F and an average low of 45°F.
Don't let those numbers fool you.
Averages are just math, and the weather in the Valley of the Sun doesn't care about math. In December 2024, Phoenix actually smashed records, hitting a bizarrely balmy 83°F on December 3rd. Then, by mid-month, the lows were dipping toward the low 40s.
Basically, you aren't experiencing "67 degrees." You are experiencing a 30-degree swing every single day. The sun in the desert is intense. Even when it's 65 degrees out, if you're sitting in direct sunlight at a spring training stadium or on a patio in Old Town Scottsdale, it feels like 75.
Then the sun goes down.
💡 You might also like: How Far Universal Studios From Disney World Really Is (and Why It’s Tricky)
The moment that orange orb disappears, the temperature drops like a rock. If you’re out at ZooLights at the Phoenix Zoo or walking through the Las Noches de las Luminarias at the Desert Botanical Garden, you will regret every life choice that led you to leave your jacket in the hotel room.
Rain is Rare, but it Bites
Phoenix isn't Seattle. You aren't going to see weeks of gray drizzle. However, December is technically one of the "rainier" months for the Sonoran Desert.
Wait. "Rainy" is a strong word.
We’re talking about maybe an inch of rain for the entire month. But when it does rain in December, it’s usually a cold, soak-you-to-the-bone kind of rain that comes off the Pacific. It’s not the dramatic, lightning-filled monsoons of July. It’s just... chilly.
If you see clouds in the forecast, bring a real shell. The humidity might only hover around 37% (which feels like nothing to East Coasters), but combined with a 50-degree breeze? It’s enough to make a local reach for a heated vest.
What to Actually Pack (The "Expert" List)
Forget the "Ultimate Packing Guide" nonsense you see on Pinterest. Here is what you actually need for Phoenix Arizona weather in December:
- The "Base Layer" Strategy: Start with a t-shirt. Always. If you start with a sweater, you’ll be sweating by 11:00 AM.
- The Light Puffy: Those ultra-light down jackets that fold into a tiny ball? They were basically invented for Arizona winters.
- Sunscreen: Yes, in December. The UV index is lower, but the air is thin and dry. You will burn while hiking Camelback Mountain and won't realize it until you're back at the resort.
- Lip Balm: The desert air in winter is a vacuum for moisture. If you don't use Chapstick, your lips will be cracked by day three.
- A Swimsuit: Most resorts (like the Arizona Biltmore or JW Marriott Desert Ridge) heat their pools to a literal 82 degrees. You can absolutely swim in December, provided you have a robe ready for the walk back to your room.
Is December "Hiking Season"?
Absolutely. This is the peak.
In the summer, hiking in Phoenix is a death wish. In December, it's a dream. You can start a hike at 10:00 AM and not worry about heatstroke.
Popular spots like Piestewa Peak and Echo Canyon are packed this time of year. If you want a bit more breathing room, head over to the McDowell Sonoran Preserve in North Scottsdale. The air is crisp, the visibility is endless, and the saguaros look particularly stoic against a deep blue winter sky.
🔗 Read more: Blue Ridge Summit PA: Why This Tiny Mountain Town Still Matters
Just a heads-up: if you’re hiking early in the morning, the trailhead might be 38 degrees. Within an hour, it'll be 55. Wear layers you can tie around your waist.
The "Golf" Factor
December is "Prime Time" for golf in the Valley. This is why hotel prices triple.
Because the Phoenix Arizona weather in December is so stable—usually clear skies and light winds—golfers flock here from the Midwest. If you’re playing, remember that the "morning dew" in the desert is real and cold. Your 7:00 AM tee time will require a windbreaker and maybe some gloves. By the back nine, you'll be in a polo.
Common Misconceptions
People think they’ll see snow. You won't.
Unless you drive two hours north to Flagstaff, snow in Phoenix is a "once-every-twenty-years" event that shuts down the entire city because nobody knows how to drive on it. What you might see is frost. If you’re staying in the "outlying" areas like Buckeye, Queen Creek, or North Peoria, the overnight lows can actually hit freezing.
The urban heat island effect keeps downtown Phoenix and Scottsdale a few degrees warmer, but the desert floor is a master at radiating heat back into space.
Actionable Next Steps for Your Trip
To make the most of the Phoenix Arizona weather in December, don't just wing it.
First, check the "Dew Point" rather than just the high temperature. If the dew point is exceptionally low, the temperature swing at sunset will be even more violent.
Second, book your outdoor dining for lunch. Everyone wants to eat dinner on the patio, but by 7:00 PM, most restaurants have to blast the propane heaters just to keep people from shivering. A patio lunch in 68-degree sun is the peak Arizona experience.
Finally, hydrate more than you think. You won't feel thirsty because you aren't sweating like a pig in the humidity, but the dry December air is constantly dehydrating you. Drink a glass of water for every cocktail or coffee you have.
📖 Related: Darling River New South Wales: Why Australia’s Iconic Waterway is Facing a Make-or-Break Year
If you prepare for the 30-degree "Desert Dip" at sunset, December in Phoenix will likely be the best weather you’ve ever experienced. Just don't be the guy in the parka—or the kid in the flip-flops. Aim for the middle.