Iowa City weather in December

In December, Iowa City sees average daytime highs of 34°F and overnight lows near 20°F, with 1.9 in of precipitation across 6.9 wet days and about 9 hours of daylight. It is the 10th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 39°F in the first days to 31°F by the end. The sky is clear or mostly clear about 26% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 12 min at the start of December to 9 hours by month's end. Set against the rest of the year, December is Iowa City's 11th-clearest and 7th-windiest month. For the whole year in context, see Iowa City's year-round climate.

Daytime high
34°
10th warmest
Overnight low
20°
3rd coldest
Precipitation
1.9 in
6.9 wet days
Daylight
9 hours
7:32 AM – 4:32 PM
Cloud cover
66%
11th clearest
Wind
9 mph
7th windiest
Solar energy
1.74 kWh/m²
Travel score
0.0
out of 10

Iowa City is city in Johnson County, Iowa, United States.

Density
1,093/km²
people per km²
Founded
1839

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 39°F in the first days to 31°F by the end.

A typical December day in Iowa City reaches about 34°F in the afternoon and slips back to 20°F overnight — a 14°F spread between the day's warmth and the night's chill. On most days the high lands between 18°F and 49°F. Set against its neighbours, December runs about 13°F cooler than November and about 5°F warmer than January.

20°40°60°151015202531
Avg high (°F)Avg low (°F)
14025
23924
33924
43824
53823
63723
73722
83622
93622
103621
113521
123521
133520
143420
153420
163420
173319
183319
193319
203319
213319
223219
233218
243218
253218
263218
273217
283117
293117
303117
313117

How December really feels in Iowa City

Once humidity and wind are folded in, December averages 0 days that feel above 90°F and 31 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
31
28 feel bitter (≤ 14°F)

The story in December is cold — wind chill drags the overnight "feels like" below the raw low.

Iowa City weather by month

How December compares with the rest of the year at a glance. December is the 10th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan29° / 14°1.57.15.39.30.0
Feb33° / 18°1.86.44.210.30.0
Mar47° / 29°2.79.22.811.71.6
Apr60° / 41°4.411.80.813.14.5
May71° / 52°4.913.4014.36.0
Jun80° / 62°5.111.70156.3
Jul83° / 65°3.79.6014.76.1
Aug81° / 63°3.89.1013.76.8
Sep75° / 55°3.98.2012.37.2
Oct62° / 43°2.98.60.210.95.5
Nov47° / 31°2.37.71.59.71.7
Dec34° / 20°1.96.94.590.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 26% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 11% of December, with mostly cloudy or overcast conditions the remaining 63%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13961
24060
34060
44060
53961
63961
73961
83961
93862
103961
113961
123862
133862
143763
153763
163664
173664
183664
193763
203664
213664
223763
233664
243664
253664
263565
273565
283664
293664
303565
313565

Chance of precipitation in December

Any precipitationSnow

Iowa City gets around 1.9 in of rain and snow over 6.9 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 23% and peaks near 25% on the wettest days, and about 5 days bring snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
12511
22512
32512
42413
52413
62414
72414
82414
92314
102314
112314
122314
132314
142314
152314
162214
172214
182214
192214
202214
212214
222114
232114
242114
252114
262114
272114
282214
292214
302214
312214

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)
1100
2100
3100
4100
5100
6100
7100
8100
9100
10100
11100
12100
13100
14100
15100
16100
17100
18100
19100
20100
21100
22100
23100
24100
25100
26100
27100
28100
29100
30100
31100

Wind in December

Winds average 9 mph in December.

Across December, daily wind ranges from about 9 mph on the calmest days to 10 mph at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (mph)Feels
19light breeze
29light breeze
39light breeze
49light breeze
59light breeze
69light breeze
79light breeze
89light breeze
99light breeze
109light breeze
119light breeze
129light breeze
139light breeze
149light breeze
159light breeze
169light breeze
179light breeze
189light breeze
199light breeze
209light breeze
219light breeze
229light breeze
239light breeze
249light breeze
259light breeze
269light breeze
279light breeze
289light breeze
2910light breeze
3010light breeze
3110light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 12 min at the start of December to 9 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 7:20 AM to 7:39 AM, and sunset from 4:32 PM to 4:40 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.27:204:32
29.27:214:32
39.27:224:31
49.17:234:31
59.17:244:31
69.17:254:31
79.17:264:31
89.17:264:31
99.17:274:31
109.17:284:31
119.07:294:31
129.07:304:31
139.07:304:31
149.07:314:32
159.07:324:32
169.07:324:32
179.07:334:32
189.07:344:33
199.07:344:33
209.07:354:33
219.07:354:34
229.07:364:34
239.07:364:35
249.07:374:35
259.07:374:36
269.07:374:36
279.07:384:37
289.07:384:38
299.07:384:38
309.07:394:39
319.07:394:40

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.74 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.74 kWh/m² to a high of 6.39 kWh/m² in July across the year — December's 1.74 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.8Dim
21.8Dim
31.8Dim
41.8Dim
51.8Dim
61.8Dim
71.8Dim
81.8Dim
91.8Dim
101.8Dim
111.7Dim
121.7Dim
131.7Dim
141.7Dim
151.7Dim
161.7Dim
171.7Dim
181.7Dim
191.7Dim
201.7Dim
211.7Dim
221.7Dim
231.7Dim
241.8Dim
251.8Dim
261.8Dim
271.8Dim
281.8Dim
291.8Dim
301.8Dim
311.8Dim
Planning a trip in December

Is December a good time to visit Iowa City?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

0.0
Sightseeing
10th-best month of the year
0.0
Beach & pool
10th-best month of the year

December is a weaker month for outdoor sightseeing in Iowa City.

What to pack for Iowa City in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Iowa City sees daytime highs around 34°F and nights near 20°F. Pack a warm layer and a heavy coat. About 7 days see rain.

a warm layera heavy coat

UV index in Iowa City in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 2. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Iowa City peaks around June 19 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJun 19UV 9Dec 20UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov3Moderate
Dec2Low

Air quality in Iowa City in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Iowa City is worst in July — around 17 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 8 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateGoodJul 1916 µg/m³Oct 218 µg/m³
PM2.5 (µg/m³)Level
Jan12Moderate
Feb14Moderate
Mar14Moderate
Apr11Good
May13Moderate
Jun13Moderate
Jul17Moderate
Aug15Moderate
Sep12Good
Oct8Good
Nov8Good
Dec10Good
Location & terrain

Where is Iowa City?

Iowa City sits at 41.7°N, 91.5°W, 669 ft above sea level, in United States. The nearest listed city is Coralville, 3.1 mi away.

Topography around Iowa City

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Iowa City.

Within 2 miles, the terrain around Iowa City has only modest variations in elevation — a maximum elevation change of 223 ft around an average of 715 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 384 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 646 ft.

The land around Iowa City is covered by trees (50%) and artificial surfaces (31%) within 2 miles, cropland (57%) within 10 miles, and cropland (72%) within 50 miles.

2 miles
223 ft
10 miles
384 ft
50 miles
646 ft
treesgrasslandcroplandartificial surfaceswater
December weather nearby: Coralville 3.1 mi · North Liberty 6.8 mi · Cedar Rapids 25 mi · Marion 26 mi · Muscatine 30 mi · Davenport 50 mi · Rock Island 50 mi · Bettendorf 53 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Iowa City (41.6611°, -91.5302°, elevation 669 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).