Oconomowoc weather in August

In August, Oconomowoc sees average daytime highs of 79°F and overnight lows near 62°F, with 3.5 in of rain across 10.3 wet days and about 13.8 hours of daylight. It is the 2nd-warmest and 4th-wettest month of the year here.

Day-to-day highs hold fairly steady near 79°F through the month. The sky is clear or mostly clear about 35% of the time in August, and the air most often feels comfortable.

Daylight stretches from about 14 h 24 min at the start of August to 13 h 06 min by month's end. Set against the rest of the year, August is Oconomowoc's 3rd-clearest and 12th-windiest month. For the whole year in context, see Oconomowoc's year-round climate.

Daytime high
79°
2nd warmest
Overnight low
62°
11th coldest
Rainfall
3.5 in
10.3 wet days
Daylight
13 h 48 min
5:05 AM – 6:52 PM
Cloud cover
55%
3rd clearest
Wind
6 mph
12th windiest
Solar energy
5.27 kWh/m²
Travel score
6.7
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 August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 79°F through the month.

A typical August day in Oconomowoc reaches about 79°F in the afternoon and slips back to 62°F overnight — a 17°F spread between the day's warmth and the night's chill. On most days the high lands between 71°F and 87°F. Set against its neighbours, August runs about 2°F cooler than July and about 7°F warmer than September.

50°60°70°80°90°151015202531
Avg high (°F)Avg low (°F)
18163
28063
38063
48063
58063
68063
78062
88062
98062
108062
117962
127962
137962
147962
157962
167962
177962
187962
197961
207961
217961
227961
237961
247861
257861
267861
277860
287860
297860
307860
317759

How August really feels in Oconomowoc

Once humidity and wind are folded in, August averages 0 days that feel above 90°F and 0 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
0
wind chill below the day's low

August sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Oconomowoc weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 4th-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 August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 35% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 19% of August, with mostly cloudy or overcast conditions the remaining 46%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15644
25644
35545
45545
55545
65446
75347
85248
95248
105248
115248
125248
135248
145248
155248
165248
175248
185347
195248
205248
215347
225347
235446
245446
255446
265644
275644
285743
295743
305842
315842

Chance of precipitation in August

Any precipitation

Oconomowoc gets around 3.5 in of rain over 10.3 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 32% and peaks near 35% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
135
235
334
434
534
633
733
833
932
1032
1132
1232
1332
1432
1532
1632
1733
1833
1933
2033
2133
2233
2333
2433
2532
2632
2731
2830
2930
3029
3128

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the comfortable band about 27% of days. Sticky, muggy-or-worse air turns up on roughly 28% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1162627229
2162627219
3162727219
4172626219
5172726219
6172726219
7182725219
8182725219
9182725218
10192825218
11192825218
12192825217
13192825217
14192825217
15192825216
16192825226
17192825226
18192825235
19192825235
20192725235
21192725245
22192725245
23202725235
24202725235
25212725235
26222724225
27232724225
28242624215
29262624204
30272623194
31292623184

Wind in August

Winds average 6 mph in August, the calmest month.

Across August, daily wind ranges from about 6 mph on the calmest days to 6 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm
316calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 24 min at the start of August to 13 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 78 minutes over August. Sunrise moves from 4:48 AM to 5:22 AM, and sunset from 7:12 PM to 6:26 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.44:487:12
214.44:497:11
314.34:507:09
414.34:517:08
514.24:537:07
614.24:547:06
714.24:557:04
814.14:567:03
914.14:577:02
1014.04:587:00
1114.04:596:59
1214.05:006:57
1313.95:016:56
1413.95:026:55
1513.85:046:53
1613.85:056:52
1713.75:066:50
1813.75:076:48
1913.65:086:47
2013.65:096:45
2113.65:106:44
2213.55:116:42
2313.55:136:40
2413.45:146:39
2513.45:156:37
2613.35:166:35
2713.35:176:33
2813.25:186:32
2913.25:196:30
3013.15:206:28
3113.15:226:26

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.27 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 — August's 5.27 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.8Bright
25.7Bright
35.7Bright
45.7Bright
55.6Bright
65.6Bright
75.5Bright
85.5Bright
95.5Bright
105.4Bright
115.4Bright
125.4Bright
135.3Bright
145.3Bright
155.3Bright
165.3Bright
175.2Bright
185.2Bright
195.2Bright
205.2Bright
215.1Bright
225.1Bright
235.1Bright
245.1Bright
255.0Bright
265.0Bright
275.0Bright
285.0Bright
294.9Bright
304.9Bright
314.9Bright
Planning a trip in August

Is August a good time to visit Oconomowoc?

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

6.7
Sightseeing
2nd-best month of the year
6.5
Beach & pool
2nd-best month of the year

August is a reasonable time to visit Oconomowoc for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Oconomowoc in August

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

In August, Oconomowoc sees daytime highs around 79°F and nights near 62°F. Worth packing: light clothes, rain gear and sun protection. About 10 days see rain.

light clothesrain gearsun protection

Sea temperature near Oconomowoc in August

The nearest coast averages about 70°F in August — 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 August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 8 — enough to warrant sun protection. 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 August

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where August 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
August 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).