Oconomowoc weather in January

In January, Oconomowoc sees average daytime highs of 28°F and overnight lows near 14°F, with 1.7 in of precipitation across 8.2 wet days and about 9.2 hours of daylight. It is the 12th-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near 28°F through the month. The sky is clear or mostly clear about 21% of the time in January, and the air most often feels dry.

Daylight stretches from about 8 h 54 min at the start of January to 9 h 36 min by month's end. Set against the rest of the year, January is Oconomowoc's 12th-clearest and 6th-windiest month. For the whole year in context, see Oconomowoc's year-round climate.

Daytime high
28°
12th warmest
Overnight low
14°
1st coldest
Precipitation
1.7 in
8.2 wet days
Daylight
9 h 06 min
7:29 AM – 4:38 PM
Cloud cover
71%
12th clearest
Wind
8 mph
6th windiest
Solar energy
1.86 kWh/m²
Travel score
0.0
out of 10

Oconomowoc is city in Waukesha County, Wisconsin, United States.

Founded
1837

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

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 28°F through the month.

A typical January day in Oconomowoc reaches about 28°F in the afternoon and slips back to 14°F overnight — a 14°F spread between the day's warmth and the night's chill. On most days the high lands between 12°F and 41°F. Set against its neighbours, January runs about 5°F cooler than December and about 4°F cooler than February.

20°40°151015202531
Avg high (°F)Avg low (°F)
13016
23016
32916
42916
52915
62915
72915
82915
92814
102814
112814
122814
132814
142813
152813
162713
172713
182713
192713
202713
212713
222713
232713
242713
252813
262813
272813
282813
292813
302814
312814

How January really feels in Oconomowoc

Once humidity and wind are folded in, January 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 January is cold — wind chill drags the overnight "feels like" below the raw low.

Oconomowoc weather by month

How January compares with the rest of the year at a glance. January is the 12th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan28° / 14°1.78.26.89.20.0
Feb32° / 17°1.775.710.20.0
Mar44° / 27°2.39.44.111.60.9
Apr56° / 38°3.911.91.613.13.7
May68° / 49°3.811.9014.45.9
Jun78° / 59°3.811.4015.16.5
Jul81° / 64°3.49.7014.96.5
Aug79° / 62°3.510.3013.86.7
Sep72° / 54°2.98.5012.36.9
Oct59° / 42°2.890.310.84.7
Nov45° / 31°2.18.229.51.0
Dec33° / 20°2.07.75.18.90.0

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 21% of the time in January, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 12% of January, with mostly cloudy or overcast conditions the remaining 67%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13268
23169
33169
43169
53169
63070
73070
83070
93070
103169
113169
123169
133268
143268
153367
163367
173466
183466
193466
203466
213565
223466
233466
243466
253565
263565
273565
283565
293565
303565
313466

Chance of precipitation in January

Any precipitationSnow

Oconomowoc gets around 1.7 in of rain and snow over 8.2 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 26% and peaks near 28% on the wettest days, and about 7 days bring snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
12518
22518
32619
42619
52720
62721
72821
82822
92822
102823
112823
122823
132823
142824
152824
162824
172724
182724
192623
202623
212523
222522
232522
242422
252422
262422
272422
282422
292421
302421
312321

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, January 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 January

Winds average 8 mph in January.

Across January, daily wind ranges from about 8 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (mph)Feels
18light breeze
28light breeze
38light breeze
48light breeze
58light breeze
68light breeze
78light breeze
88light breeze
98light breeze
108light breeze
118light breeze
128light breeze
138light breeze
148light breeze
158light breeze
168light breeze
178light breeze
188light breeze
198light breeze
208light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze
318light breeze

Sunrise & sunset in January

DaylightNight

Daylight runs from about 8 h 54 min at the start of January to 9 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 42 minutes over January. Sunrise moves from 7:31 AM to 7:19 AM, and sunset from 4:23 PM to 4:56 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
18.97:314:23
28.97:314:24
38.97:314:25
48.97:314:26
58.97:314:26
68.97:314:27
78.97:314:28
89.07:314:29
99.07:314:30
109.07:314:31
119.07:314:32
129.07:304:33
139.17:304:34
149.17:304:35
159.17:294:37
169.17:294:38
179.27:284:39
189.27:284:40
199.27:274:41
209.37:274:42
219.37:264:43
229.37:264:45
239.37:254:46
249.47:244:47
259.47:244:48
269.47:234:50
279.57:224:51
289.57:214:52
299.67:204:53
309.67:204:55
319.67:194:56

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 1.86 kWh/m².

For context, solar energy here swings from a low near 1.55 kWh/m² to a high of 6.29 kWh/m² in June across the year — January's 1.86 kWh/m² sits near the bottom.

0123151015202531
Solar energy (kWh/m²)Level
11.6Dim
21.6Dim
31.6Dim
41.6Dim
51.6Dim
61.6Dim
71.7Dim
81.7Dim
91.7Dim
101.7Dim
111.7Dim
121.8Dim
131.8Dim
141.8Dim
151.8Dim
161.9Dim
171.9Dim
181.9Dim
191.9Dim
202.0Dim
212.0Dim
222.0Moderate
232.0Moderate
242.1Moderate
252.1Moderate
262.1Moderate
272.2Moderate
282.2Moderate
292.2Moderate
302.3Moderate
312.3Moderate
Planning a trip in January

Is January a good time to visit Oconomowoc?

Our two travel scores rate January 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
8th-best month of the year

January is a weaker month for outdoor sightseeing in Oconomowoc.

What to pack for Oconomowoc in January

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

In January, Oconomowoc sees daytime highs around 28°F and nights near 14°F. Pack a warm layer and a heavy coat. Worth having: rain gear. About 8 days see rain.

a warm layera heavy coatrain gear

Sea temperature near Oconomowoc in January

The nearest coast averages about 38°F in January — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 32 mi away) is warmest in August at about 70°F and coldest in March near 36°F.

It's comfortable for a long swim from Jul 29 to Aug 30 — about 1.1 months when the water holds above 68°F.

30°40°50°60°70°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarm
Sea temperature (°F)Comfort
Jan38Bracing
Feb36Bracing
Mar36Bracing
Apr38Bracing
May42Bracing
Jun54Bracing
Jul67Cool
Aug70Refreshing
Sep66Cool
Oct56Bracing
Nov46Bracing
Dec41Bracing

UV index in Oconomowoc in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 1. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Oconomowoc peaks around June 20 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 1 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 20UV 9Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar4Moderate
Apr6High
May8Very high
Jun9Very high
Jul8Very high
Aug8Very high
Sep6High
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Oconomowoc in January

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Oconomowoc is worst in July — around 17 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (October, 9 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodJul 1616 µg/m³Oct 239 µg/m³
PM2.5 (µg/m³)Level
Jan12Good
Feb14Moderate
Mar15Moderate
Apr13Moderate
May15Moderate
Jun16Moderate
Jul17Moderate
Aug15Moderate
Sep12Moderate
Oct9Good
Nov9Good
Dec10Good
Location & terrain

Where is Oconomowoc?

Oconomowoc sits at 43.1°N, 88.5°W, 863 ft above sea level, in United States. The nearest listed city is Watertown, 13 mi away.

Topography around Oconomowoc

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

Within 2 miles, the terrain around Oconomowoc has only modest variations in elevation — a maximum elevation change of 148 ft around an average of 879 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 440 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 846 ft.

The land around Oconomowoc is covered by trees (35%), grassland (23%) and artificial surfaces (20%) within 2 miles, trees (36%), cropland (31%) and grassland (24%) within 10 miles, and cropland (44%) and trees (23%) within 50 miles.

2 miles
148 ft
10 miles
440 ft
50 miles
846 ft
treesgrasslandcroplandartificial surfaceswaterwetland
January weather nearby: Watertown 13 mi · Waukesha 15 mi · Menomonee Falls 20 mi · Brookfield 20 mi · Germantown 21 mi · New Berlin 22 mi · Muskego 23 mi · Mequon 25 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 Oconomowoc (43.1117°, -88.4993°, elevation 863 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).