Climate and average weather in Onalaska

In Onalaska, the summers are warm, showery, and partly cloudy and the winters are very cold, snowy, and partly cloudy.

Best: mid May to early October

Over the course of the year, the temperature in Onalaska typically varies from 10°F to 81°F, and is rarely below -10°F or above 89°F. July is the hottest month of the year, while January is the coldest.

Based on the travel score, the best time of year to visit Onalaska for warm-weather activities is from mid May to early October.

Hottest
Jul
81°
Coldest
Jan
10°
Wettest
Jun
4.8 in
Driest
Feb
1.2 in
Rain / yr
34.4 in
111 wet days
Daylight
8.7–15.3 h
shortest–longest
Elevation
709 ft
43.9°N
Clearest
Sep
52% cloud

Onalaska is fourth-class city in La Crosse County, Wisconsin, United States.

Density
659/km²
people per km²
Founded
1851

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

Onalaska weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around mid May to early October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Onalaska, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 4.5 months, from May 14 to September 26, with daily high temperatures above 67°F. The hottest month of the year in Onalaska is July, with an average high of 81°F and low of 64°F.

The cool season lasts 3.1 months, from November 29 to March 3, with daily high temperatures below 36°F. The coldest month of the year in Onalaska is January, with an average low of 10°F and high of 26°F.

Days typically run about 17°F warmer than nights year-round.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)Avg low (°F)
Jan2610
Feb3014
Mar4326
Apr5638
May6849
Jun7760
Jul8164
Aug7861
Sep7153
Oct5841
Nov4329
Dec3017

How hot and cold Onalaska really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the coldest nights, wind chill pulls the feels-like down to about -2°F (around January 17), with roughly 173 freezing days a year (feels-like at or below 32°F) 102 of them bitterly cold — worst in January.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°F)Air high (°F)Feels-like low (°F)Air low (°F)
Jan2626-110
Feb3030314
Mar43431726
Apr56563238
May68684749
Jun77776060
Jul81816464
Aug79786161
Sep71715253
Oct58583641
Nov43432129
Dec3030717

Average hourly temperature in Onalaska

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on July afternoons, near 81°F, and coldest before dawn in January, near 10°F.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Onalaska weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan26° / 10°1.376.49.10.0
Feb30° / 14°1.26.15.110.20.0
Mar43° / 26°2.38.94.111.60.7
Apr56° / 38°3.611.5213.23.7
May68° / 49°4.212.80.114.55.8
Jun77° / 60°4.812.3015.26.3
Jul81° / 64°3.910.6014.96.5
Aug78° / 61°3.69.3013.86.9
Sep71° / 53°3.29.4012.36.8
Oct58° / 41°2.88.80.510.84.4
Nov43° / 29°2.06.839.50.7
Dec30° / 17°1.57.168.80.0

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Onalaska gets about 34.4 in of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.

The wetter season lasts 4.4 months, from around Mar 23 to Aug 3, peaking in May at about 43% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Feb 8.

June is the wettest month by volume, with 4.8 in over about 12 wet days; February is the driest, with 1.2 in. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetMay 30 · 43%Feb 8 · 20%
Rain on a day (%)Rain days
Jan237
Feb226
Mar299
Apr3812
May4113
Jun4112
Jul3411
Aug309
Sep319
Oct289
Nov237
Dec237

Monthly rainfall

Over a full year, Onalaska collects about 34.4 in of rain across 111 wet days — roughly 2.9 in in an average month.

It doesn’t fall evenly. June is the wettest month with 4.8 in, while February is the driest at just 1.2 in. The three wettest months alone bring about 37% of the year’s total, and some of the cold-season precipitation falls as snow.

0123456JanFebMarAprMayJunJulAugSepOctNovDec1.31.22.33.64.24.83.93.63.22.82.01.5
Rainfall (in)Rain daysSnow days
Jan1.376
Feb1.265
Mar2.394
Apr3.6122
May4.2130
Jun4.8120
Jul3.9110
Aug3.690
Sep3.290
Oct2.891
Nov2.073
Dec1.576

Snow in Onalaska

Average snowy days through the year, the snow-season span, and estimated snowfall — for ski trips and the perennial 'will there be snow at Christmas?' question.

Onalaska averages about 27 snowy days a year. Snow season runs roughly Oct 15 to May 1 — about 6.5 months.

January is snowiest, with roughly 6 days of snow and an estimated 11 in of snowfall. Over the year that adds up to an estimated 51 in of snow.

02468JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonJan 20
Snow daysSnowfall (in)
Jan611
Feb510
Mar49
Apr26
May00
Jun00
Jul00
Aug00
Sep00
Oct11
Nov35
Dec610

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Onalaska, the average share of the sky covered by clouds shows moderate seasonal variation over the course of the year.

The clearer part of the year begins around May 28 and lasts for 4.7 months, ending around October 18. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 57% of the time on average.

The cloudier part of the year begins around October 19 and lasts for 7.3 months, ending around May 27. The cloudiest month is December, when it is overcast or mostly cloudy 67% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecAug 31 · 60%Dec 20 · 32%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan3367
Feb3763
Mar4060
Apr3763
May3961
Jun4852
Jul5743
Aug5743
Sep5545
Oct4555
Nov3763
Dec3367

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 15, brings about 15 h 18 min of light; the shortest, around December 15, only 8 h 42 min — a swing of roughly 6 h 36 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.17:424:46
Feb10.27:145:25
Mar11.66:266:03
Apr13.25:296:41
May14.54:457:17
Jun15.24:277:43
Jul14.94:417:40
Aug13.85:147:04
Sep12.35:506:08
Oct10.86:275:13
Nov9.57:084:32
Dec8.87:394:23

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Onalaska averages about 9 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 6 and 13 days.

The sunnier stretch runs 4.4 months, from around Jun 10 to Oct 22. The sunniest month is September, with roughly 12 sunny days (mixed).

The greyest month is December, down near 6 sunny days — about 45% fewer than the September peak.

051015JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedSep 413 daysDec 226 days
Sunny daysSky
Jan7Gloomy
Feb8Mixed
Mar8Gloomy
Apr7Gloomy
May7Gloomy
Jun9Mixed
Jul11Mixed
Aug12Mixed
Sep12Mixed
Oct10Mixed
Nov8Gloomy
Dec7Gloomy

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In Onalaska, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 3.8 months, from around May 27 to September 20. The muggiest month is July, when the air feels humid, muggy or worse about 60% of the time.

The most comfortable stretch runs from around September 21 to May 26, and March is the most comfortable month — the air is dry or comfortable 100% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecMar 9 · 100%Jul 20 · 37%oppressivemuggyhumiddrycomfortablecomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan10000000
Feb10000000
Mar9910000
Apr9820000
May81116200
Jun3725231420
Jul1525282391
Aug2027282050
Sep591814710
Oct9442100
Nov10000000
Dec10000000

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Onalaska is typically calm, near 7 mph, and varies little with the seasons.

The windier part of the year lasts 8.1 months, from around Sep 20 to May 23. The windiest month is April, averaging about 8 mph (light breeze).

The calmer part of the year runs from around May 24 to Sep 19, with August the calmest month at about 6 mph.

051015JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezebreezyApr 11 · 8 mphAug 6 · 6 mph
Wind speed (mph)Feels
Jan8light breeze
Feb8light breeze
Mar8light breeze
Apr8light breeze
May8light breeze
Jun7calm
Jul6calm
Aug6calm
Sep7calm
Oct8light breeze
Nov8light breeze
Dec8light breeze

Best time to visit Onalaska

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Onalaska throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around late May, Onalaska is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 64°F and 82°F. Based on this score, the best time of year to visit Onalaska for general outdoor tourist activities is from mid May to early October, with a peak score in the first week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationSep 3 · 7.2

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan0.0poor
Feb0.0poor
Mar0.8poor
Apr3.7fair
May5.8good
Jun6.3good
Jul6.5good
Aug6.9good
Sep6.7good
Oct4.3fair
Nov0.8poor
Dec0.0poor

The beach/pool score favors clear, rainless days with daytime highs between 75°F and 93°F. Based on this score, the best time of year to visit Onalaska for hot-weather activities is from early June to mid September, with a peak score in the last week of July.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationJul 30 · 6.7

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Onalaska, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around July (highs near 81°F), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 26°F), pack a warm layer and a heavy coat.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Onalaska sees daytime highs around 81°F and nights near 64°F. Pack light clothes and sun protection. Worth having: rain gear. About 11 days see rain.

UV index (midday) in Onalaska by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Onalaska peaks around June 14 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 11 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 14UV 9Jan 11UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar3Moderate
Apr5High
May8Very high
Jun9Very high
Jul7High
Aug7Very high
Sep6High
Oct3Moderate
Nov2Low
Dec1Low

Average hourly UV index in Onalaska

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in June the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan00
Feb00
Mar30
Apr5.50
May84.5
Jun8.55
Jul7.53.5
Aug73.5
Sep60
Oct20
Nov00
Dec00
Almanac & agriculture

Growing season

Chance of a frost-free dayTypical season (≥50%)

The growing season in Onalaska typically lasts about 223 days, from around March 30 to November 7 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 25 to October 11.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonFeb 1810%Mar 3050%Apr 2590%Oct 1190%Nov 750%Dec 2610%
Frost-free chance (%)Frost nights
Jan731
Feb1028
Mar3031
Apr7622
May980
Jun1000
Jul1000
Aug1000
Sep990
Oct8520
Nov3830
Dec1231

Growing degree days

Degree days (base 50°F)Frost-free shaded

Growing degree days tally heat above 50°F: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Onalaska banks about 2,539 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

01,0002,0003,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°F·days)
Jan0
Feb0
Mar0
Apr11
May269
Jun553
Jul686
Aug613
Sep365
Oct42
Nov0
Dec0

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Onalaska receives about 3.9 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 1.5 and 6.4 kWh/m².

The brighter stretch of the year lasts 6.2 months, from around Mar 14 to Sep 19. The brightest month is July, averaging about 6.2 kWh/m² (intense).

The dimmest month is December, down near 1.5 kWh/m² — roughly 76% less than the July peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJul 26.4 kWhDec 201.5 kWh
Solar energy (kWh/m²)Level
Jan1.8Dim
Feb2.9Moderate
Mar4.0Moderate
Apr4.9Bright
May5.6Bright
Jun6.2Intense
Jul6.2Intense
Aug5.3Bright
Sep4.2Bright
Oct2.8Moderate
Nov1.9Dim
Dec1.5Dim

Where is Onalaska?

Onalaska sits at 43.9°N, 91.2°W, 709 ft above sea level, in United States. The nearest listed city is North La Crosse, 2.5 mi away.

Topography around Onalaska

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

Within 2 miles, the terrain around Onalaska has only modest variations in elevation — a maximum elevation change of 581 ft around an average of 696 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 748 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 860 ft.

The land around Onalaska is covered by artificial surfaces (34%), trees (28%) and grassland (21%) within 2 miles, trees (53%) within 10 miles, and trees (54%) and cropland (33%) within 50 miles.

2 miles
581 ft
10 miles
748 ft
50 miles
860 ft
treesgrasslandcroplandartificial surfaceswaterwetland
Nearby: North La Crosse 2.5 mi · La Crosse 5.6 mi · Winona 23 mi · Rochester 62 mi · Eau Claire 65 mi · Marshfield 76 mi · Menomonie 76 mi · Wisconsin Rapids 78 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 Onalaska (43.8844°, -91.2351°, elevation 709 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).