Waterloo weather in December

In December, Waterloo sees average daytime highs of 32°F and overnight lows near 18°F, with 1.7 in of precipitation across 6.9 wet days and about 8.9 hours of daylight. It is the 10th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 37°F in the first days to 29°F by the end. The sky is clear or mostly clear about 24% of the time in December, and the air most often feels dry.

Daylight stretches from about 9 h 06 min at the start of December to 8 h 54 min by month's end. Set against the rest of the year, December is Waterloo's 11th-clearest and 7th-windiest month. For the whole year in context, see Waterloo's year-round climate.

Daytime high
32°
10th warmest
Overnight low
18°
3rd coldest
Precipitation
1.7 in
6.9 wet days
Daylight
8 h 54 min
7:39 AM – 4:33 PM
Cloud cover
68%
11th clearest
Wind
10 mph
7th windiest
Solar energy
1.7 kWh/m²
Travel score
0.0
out of 10

Waterloo is city in Black Hawk County, Iowa, United States.

Density
418/km²
people per km²
Founded
1868

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 37°F in the first days to 29°F by the end.

A typical December day in Waterloo reaches about 32°F in the afternoon and slips back to 18°F overnight — a 14°F spread between the day's warmth and the night's chill. On most days the high lands between 15°F and 46°F. Set against its neighbours, December runs about 13°F cooler than November and about 6°F warmer than January.

20°40°60°151015202531
Avg high (°F)Avg low (°F)
13823
23722
33722
43621
53521
63520
73520
83420
93419
103319
113319
123318
133218
143218
153218
163117
173117
183117
193117
203017
213016
223016
233016
243016
252915
262915
272915
282915
292915
302914
312814

How December really feels in Waterloo

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
31 feel bitter (≤ 14°F)

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

Waterloo 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
Jan26° / 11°1.46.85.69.20.0
Feb31° / 15°1.46.54.810.30.0
Mar45° / 27°2.593.411.61.1
Apr59° / 39°4.311.21.113.14.3
May70° / 51°5.0130.114.46.0
Jun79° / 61°5.112.4015.16.3
Jul82° / 64°4.210.3014.86.5
Aug80° / 61°3.99.5013.76.8
Sep73° / 53°3.78.6012.37.1
Oct60° / 41°2.88.30.410.85.2
Nov45° / 29°2.17.22.19.61.2
Dec32° / 18°1.76.95.18.90.0

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 24% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 12% of December, with mostly cloudy or overcast conditions the remaining 64%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13961
23862
33862
43862
53862
63862
73862
83763
93763
103664
113664
123664
133664
143565
153664
163565
173466
183565
193565
203565
213466
223565
233565
243565
253565
263565
273565
283664
293664
303664
313664

Chance of precipitation in December

Any precipitationSnow

Waterloo gets around 1.7 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 22% and peaks near 23% on the wettest days, and about 5 days bring snow.

0%10%20%30%151015202531
Rain chance (%)Snow chance (%)
12313
22313
32314
42314
52315
62315
72315
82215
92215
102215
112216
122115
132115
142115
152115
162115
172116
182116
192116
202116
212116
222116
232117
242217
252217
262217
272216
282216
292216
302216
312116

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 10 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
110light breeze
210light breeze
310light breeze
410light breeze
59light breeze
69light breeze
79light breeze
89light breeze
99light breeze
109light breeze
119light breeze
129light breeze
139light breeze
149light breeze
159light breeze
1610light breeze
1710light breeze
1810light breeze
1910light breeze
2010light breeze
2110light breeze
2210light breeze
2310light breeze
2410light breeze
2510light breeze
2610light breeze
2710light breeze
2810light breeze
2910light breeze
3010light breeze
3110light breeze

Sunrise & sunset in December

DaylightNight

Daylight runs from about 9 h 06 min at the start of December to 8 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over December. Sunrise moves from 7:26 AM to 7:45 AM, and sunset from 4:33 PM to 4:40 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
19.17:264:33
29.17:274:32
39.17:284:32
49.17:294:32
59.07:304:32
69.07:314:32
79.07:314:32
89.07:324:32
99.07:334:32
109.07:344:32
118.97:354:32
128.97:364:32
138.97:364:32
148.97:374:32
158.97:384:32
168.97:394:33
178.97:394:33
188.97:404:33
198.97:404:33
208.97:414:34
218.97:414:34
228.97:424:35
238.97:424:35
248.97:434:36
258.97:434:36
268.97:444:37
278.97:444:37
288.97:444:38
298.97:444:39
308.97:454:40
318.97:454:40

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 1.7 kWh/m² — the year's lowest.

For context, solar energy here swings from a low near 1.7 kWh/m² to a high of 6.37 kWh/m² in July across the year — December's 1.7 kWh/m² sits near the bottom.

00.511.522.5151015202531
Solar energy (kWh/m²)Level
11.8Dim
21.8Dim
31.8Dim
41.8Dim
51.7Dim
61.7Dim
71.7Dim
81.7Dim
91.7Dim
101.7Dim
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
241.7Dim
251.7Dim
261.7Dim
271.7Dim
281.7Dim
291.7Dim
301.7Dim
311.8Dim
Planning a trip in December

Is December a good time to visit Waterloo?

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
9th-best month of the year

December is a weaker month for outdoor sightseeing in Waterloo.

What to pack for Waterloo in December

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

In December, Waterloo sees daytime highs around 32°F and nights near 18°F. Pack a warm layer and a heavy coat. About 7 days see rain.

a warm layera heavy coat

UV index in Waterloo 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 Waterloo peaks around June 18 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 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 18UV 9Jan 1UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar4Moderate
Apr6High
May7Very high
Jun9Very high
Jul8Very high
Aug7Very high
Sep6High
Oct3Moderate
Nov2Moderate
Dec2Low

Air quality in Waterloo 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 Waterloo is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (October, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateGoodJul 1916 µg/m³Oct 217 µg/m³
PM2.5 (µg/m³)Level
Jan12Moderate
Feb15Moderate
Mar14Moderate
Apr11Good
May12Good
Jun13Moderate
Jul16Moderate
Aug15Moderate
Sep12Good
Oct7Good
Nov8Good
Dec10Good
Location & terrain

Where is Waterloo?

Waterloo sits at 42.5°N, 92.3°W, 856 ft above sea level, in United States. The nearest listed city is Cedar Falls, 5.6 mi away.

Topography around Waterloo

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

Within 2 miles, the terrain around Waterloo has only modest variations in elevation — a maximum elevation change of 151 ft around an average of 873 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 243 ft; within 50 miles, only modest variations in elevation — a maximum elevation change of 620 ft.

The land around Waterloo is covered by trees (39%) and artificial surfaces (39%) within 2 miles, cropland (64%) within 10 miles, and cropland (81%) within 50 miles.

2 miles
151 ft
10 miles
243 ft
50 miles
620 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Cedar Falls 5.6 mi · Marshalltown 42 mi · Cedar Rapids 49 mi · Marion 50 mi · Mason City 63 mi · North Liberty 64 mi · Newton 66 mi · Coralville 68 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 Waterloo (42.4928°, -92.343°, elevation 856 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).