Weather in Sioux Falls in December

The month to avoid. Of the twelve, December is the one to avoid. Highs sit at -0.9 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.

December ranks 12 of 12 — near the bottom of Sioux Falls's year. September is the month that works, and the swing between the two is 54 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 -0.9 °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: 31 nights drop below freezing, so anything left outside stays frozen. Across the twenty years measured, the hottest December day reached 13.3 °C and the coldest night fell to -26.4 °C.

December is moderately variable: 2 mm in the driest year against 45 mm in the wettest, around an average of 23 mm. Roughly two Decembers in three land near that average, and the third does something else entirely.

Wind is light at 13 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 83%, which at -0.9 °C means damp rather than muggy — the kind of cold that gets into a coat and stays there.

How December sits in the year

The month is on the way down: 8.1 °C cooler than November, with January dropping another 1.8 °C. The first week and the last are not the same trip.

Daylight in December

December sits at the dark end of Sioux Falls's year — 9 hours of daylight against 15.4 at midsummer, holding steady all month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

An inland climate

Sioux Falls has no sea to moderate it, and it shows: 43 °C separates the hottest afternoon of the year from the coldest night. That is a genuinely continental range, and it means summer and winter here are barely the same place.

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 Sioux Falls versus nearby

If Sioux Falls is one option among several, the nearby comparison is worth making. Omaha is close enough to be a coin toss — 2.9 °C warmer, the same number of rain days. Minneapolis is close enough to be a coin toss — within a degree on temperature, 1 day more rain.

So: December is a compromise. September is 54 points better and is what Sioux Falls 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 Sioux Falls

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