Weather in Des Moines in December

United States · 20-year averages, December

The month to avoid. December is the month most people should skip in Des Moines. Highs sit at 1.8 °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 Des Moines's year. September is the month that works, and the swing between the two is 53 points, which is a different holiday rather than a slightly better one.

Rain falls on only 6 days, so an itinerary with no wet-weather fallback is a reasonable risk. Layers, and a genuinely waterproof outer — at 1.8 °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: 29 nights drop below freezing, so anything left outside stays frozen. Across the twenty years measured, the hottest December day reached 20.6 °C and the coldest night fell to -24.5 °C, and the wettest single day dropped 51 mm — roughly 131% of the month's rain in one day.

December is moderately variable: 9 mm in the driest year against 125 mm in the wettest, around an average of 39 mm. Roughly two Decembers in three land near that average, and the third does something else entirely.

Wind is light at 12.7 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 84%, which at 1.8 °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: 7.8 °C cooler than November, with January dropping another 2.5 °C. The first week and the last are not the same trip.

Daylight in December

December sits at the dark end of Des Moines's year — 9.2 hours of daylight against 15.2 at midsummer, holding steady all month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

An inland climate

Des Moines has no sea to moderate it, and it shows: 40.3 °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

Quiet. Few other visitors, cheaper rooms, and a real chance some seasonal operators are shut.

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

December in Des Moines versus nearby

If Des Moines is one option among several, the nearby comparison is worth making. Omaha is close enough to be a coin toss — within a degree on temperature, 1 day less rain. Kansas City is close enough to be a coin toss — 3.7 °C warmer, 1 day less rain.

So: December is a compromise. September is 51 points better and is what Des Moines 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 Des Moines

MonthHigh °CLow °CRain daysRain mmHumidity %Daylight hScore
January-0.7-9.8 523839.530
February1.6-8.9 6298110.627
March9.7-2 8487611.948
April17.14.1 10917213.371
May22.410.5 141207314.572
June27.816.6 141307415.267
July30.519.1 12947014.961
August29.517.7 121106913.964
September25.613.1 10876912.580
October17.35.4 8717111.276
November9.6-0.8 642779.948
December1.8-6.8 639849.229

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

Planning the rest of the trip

Built and maintained by Amit Sharma, Auckland, New Zealand. I build these sites so the answer is free and the data is public.

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