Weather in Denver in December

A hard month. December asks something of you. Go in knowing what. Highs sit at 7.9 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.

December ranks 11 of 12 — near the bottom of Denver's year. October is the month that works, and the swing between the two is 42 points, which is a different holiday rather than a slightly better one.

Rain falls on only 5 days, so an itinerary with no wet-weather fallback is a reasonable risk. Layers, and a genuinely waterproof outer — at 7.9 °C the difference between a good day and a miserable one is entirely down to what you are wearing.

What the averages hide

Averages flatten a month, and this one hides a few things: 23 nights drop below freezing, so anything left outside stays frozen. Across the twenty years measured, the hottest December day reached 20.7 °C and the coldest night fell to -17.6 °C, and the wettest single day dropped 26 mm — roughly 137% of the month's rain in one day.

December is moderately variable: 5 mm in the driest year against 56 mm in the wettest, around an average of 19 mm. Roughly two Decembers in three land near that average, and the third does something else entirely.

Wind is light at 9.2 km/h, so the temperature on the page is close to the temperature on your skin, and humidity is unremarkable at 56%.

How December sits in the year

Temperatures hold steady either side: 14.1 °C in November, 7.9 here, 8.4 in January. Nothing about the timing within the month matters much.

Daylight in December

December sits at the dark end of Denver's year — 9.4 hours of daylight against 15 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 — 37 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage. At 1609 m, altitude is doing as much work here as latitude: thinner air means fierce sun by day and heat that leaves the moment it sets.

How busy it gets

Off season. The genuine off season: cheapest by a distance, with the caveat that some tours and restaurants close entirely.

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

December in Denver versus nearby

If Denver is one option among several, the nearby comparison is worth making. Aspen is the weaker option in December — 8.7 °C cooler, 6 days more rain. Moab is close enough to be a coin toss — within a degree on temperature, 1 day more rain.

So: December is a compromise. October is 41 points better and is what Denver is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Denver

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