Climate and average weather in Olten

In Olten, the summers are warm, wet, and partly cloudy and the winters are cold, snowy, and partly cloudy.

Best: mid May to late September

Over the course of the year, the temperature in Olten typically varies from -1°C to 23°C, and is rarely below -7°C or above 29°C. 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 Olten for warm-weather activities is from mid May to late September.

Hottest
Jul
23°
Coldest
Jan
-1°
Wettest
Jul
170 mm
Driest
Feb
76 mm
Rain / yr
1413 mm
180 wet days
Daylight
8.3–15.7 h
shortest–longest
Elevation
406 m
47.4°N
Clearest
Jul
57% cloud
Air quality
Excellent
PM10 14 µg/m³ · 2014

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

Olten 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 late September.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

The hot season lasts 3.7 months, from May 23 to September 13, with daily high temperatures above 19°C. The hottest month of the year in Olten is July, with an average high of 23°C and low of 14°C.

The cool season lasts 3.6 months, from November 14 to March 2, with daily high temperatures below 8°C. The coldest month of the year in Olten is January, with an average low of -1°C and high of 4°C.

Days typically run about 8°C warmer than nights, with the widest day–night swing (around 9°C) in July.

-10°10°20°30°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan4-1
Feb5-1
Mar102
Apr145
May189
Jun2112
Jul2314
Aug2314
Sep1910
Oct147
Nov82
Dec40

How hot and cold Olten 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 -5°C (around January 28), with roughly 125 freezing days a year (feels-like at or below 0°C), worst in January.

-5°10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan44-4-1
Feb55-4-1
Mar1010-12
Apr141435
May181889
Jun21211212
Jul23231414
Aug23231414
Sep18191010
Oct131457
Nov7802
Dec44-30

Average hourly temperature in Olten

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 23°C, and coldest before dawn in January, near -1°C.

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

Olten weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -1°8613.37.28.70.0
Feb / -1°7611.66.89.90.2
Mar10° / 9414.65.111.62.0
Apr14° / 10615.32.313.33.5
May18° / 15417.40.214.84.7
Jun21° / 12°15518.5015.75.2
Jul23° / 14°17017.8015.35.8
Aug23° / 14°16117014.15.8
Sep19° / 10°11713.8012.45.3
Oct14° / 98130.410.63.5
Nov / 9413.23.89.11.0
Dec / -0°10114.16.78.30.0

Chance of rain

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

Olten gets about 1413 mm of precipitation a year. On a typical day the chance of rain is very wet, but that rises and falls sharply with the seasons.

The wetter season lasts 5.2 months, from around Mar 26 to Aug 30, peaking in June at about 64% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Oct 21.

July is the wettest month by volume, with 170 mm over about 18 wet days; February is the driest, with 76 mm. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%60%70%80%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetJun 10 · 64%Oct 21 · 40%
Rain on a day (%)Rain days
Jan4313
Feb4212
Mar4615
Apr5215
May5717
Jun6119
Jul5718
Aug5417
Sep4714
Oct4213
Nov4313
Dec4514

Monthly rainfall

Over a full year, Olten collects about 1413 mm of rain across 180 wet days — roughly 118 mm in an average month.

It doesn’t fall evenly. July is the wettest month with 170 mm, while February is the driest at just 76 mm. The three wettest months alone bring about 34% of the year’s total, and some of the cold-season precipitation falls as snow.

0255075100125150175200JanFebMarAprMayJunJulAugSepOctNovDec8676941061541551701611179894101
Rainfall (mm)Rain daysSnow days
Jan86137
Feb76127
Mar94155
Apr106152
May154170
Jun155190
Jul170180
Aug161170
Sep117140
Oct98130
Nov94134
Dec101147

Snow in Olten

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.

Olten averages about 33 snowy days a year. Snow season runs roughly Oct 20 to May 4 — about 6.5 months.

January is snowiest, with roughly 7 days of snow and an estimated 29 cm of snowfall. Over the year that adds up to an estimated 145 cm of snow.

0246810JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonJan 26
Snow daysSnowfall (cm)
Jan729
Feb736
Mar515
Apr213
May01
Jun00
Jul00
Aug00
Sep00
Oct02
Nov419
Dec730

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

In Olten, 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 June 9 and lasts for 3.5 months, ending around September 24. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 50% of the time on average.

The cloudier part of the year begins around September 25 and lasts for 5.5 months, ending around March 9. The cloudiest month is November, when it is overcast or mostly cloudy 72% 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%JanFebMarAprMayJunJulAugSepOctNovDecJul 28 · 54%Nov 15 · 26%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan3367
Feb3466
Mar3763
Apr3763
May3367
Jun4258
Jul5050
Aug5050
Sep4159
Oct3367
Nov2872
Dec3070

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 11, brings about 15 h 42 min of light; the shortest, around January 1, only 8 h 18 min — a swing of roughly 7 h 24 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan8.78:184:57
Feb9.97:445:42
Mar11.66:516:25
Apr13.35:487:10
May14.84:587:51
Jun15.74:378:20
Jul15.34:528:16
Aug14.15:307:35
Sep12.46:136:33
Oct10.66:555:32
Nov9.17:424:45
Dec8.38:164:33

Sunny days

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

Olten averages about 7 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 4 and 9 days.

The sunnier stretch runs 3.3 months, from around Jun 18 to Sep 25. The sunniest month is July, with roughly 9 sunny days (mixed).

The greyest month is November, down near 4 sunny days — about 48% fewer than the July peak.

051015JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedJul 299 daysNov 174 days
Sunny daysSky
Jan6Gloomy
Feb6Gloomy
Mar8Gloomy
Apr7Gloomy
May6Gloomy
Jun6Gloomy
Jul9Mixed
Aug9Mixed
Sep7Gloomy
Oct6Gloomy
Nov4Gloomy
Dec5Gloomy

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 Olten, how humid it feels changes noticeably over the year.

The more humid part of the year lasts 3.1 months, from around June 6 to September 7. The muggiest month is August, when the air feels humid, muggy or worse about 20% of the time.

The most comfortable stretch runs from around September 8 to June 5, and April 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%JanFebMarAprMayJunJulAugSepOctNovDecApr 26 · 100%Aug 4 · 74%humidcomfortabledrycomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)
Jan10000
Feb10000
Mar10000
Apr10000
May9360
Jun642610
Jul423819
Aug404020
Sep75222
Oct9730
Nov10000
Dec10000

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.

Wind in Olten is steady company: average speeds sit near 7 km/hcalm — in every month of the year, with no meaningful windy or calm season.

051015JanFebMarAprMayJunJulAugSepOctNovDeccalmlight breezeMar 16 · 8 km/hAug 9 · 6 km/h
Wind speed (km/h)Feels
Jan8calm
Feb8calm
Mar8calm
Apr7calm
May7calm
Jun7calm
Jul6calm
Aug6calm
Sep6calm
Oct6calm
Nov7calm
Dec7calm

Best time to visit Olten

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around mid September, Olten is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.

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 18°C and 28°C. Based on this score, the best time of year to visit Olten for general outdoor tourist activities is from mid May to late September, with a peak score in the last week of July.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationJul 24 · 5.9

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
Feb0.3poor
Mar2.0poor
Apr3.5poor
May4.7fair
Jun5.2fair
Jul5.8good
Aug5.8good
Sep5.3fair
Oct3.5poor
Nov1.0poor
Dec0.0poor

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Olten for hot-weather activities is from late June to late August, with a peak score in the last week of July.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationJul 27 · 4.9

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 Olten, 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 23°C), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 4°C), pack a warm layer, a heavy coat and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Olten sees daytime highs around 23°C and nights near 14°C. Pack rain gear. Worth having: light clothes and sun protection. About 18 days see rain.

UV index (midday) in Olten 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 Olten peaks around July 15 at about 8 (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 highHighModerateLowJul 15UV 8Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar4Moderate
Apr5Moderate
May7High
Jun7Very high
Jul8Very high
Aug7High
Sep4Moderate
Oct3Moderate
Nov2Low
Dec1Low

Average hourly UV index in Olten

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 July 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
Mar40
Apr5.50
May7.53
Jun84
Jul8.55
Aug73
Sep4.50
Oct10
Nov00
Dec00
Almanac & agriculture

Growing season

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

The growing season in Olten typically lasts about 282 days, from around March 1 to December 7 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 11 to November 2.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonMar 150%Apr 1190%Nov 290%Dec 750%
Frost-free chance (%)Frost nights
Jan3731
Feb3928
Mar6931
Apr9212
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct960
Nov7429
Dec4631

Growing degree days

Degree days (base 10°C)Frost-free shaded

Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Olten banks about 982 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

02505007501,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan0
Feb0
Mar0
Apr8
May103
Jun203
Jul266
Aug253
Sep129
Oct19
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.

Olten receives about 3.4 kWh/m² a day of solar energy on average — moderate — with a clear seasonal swing between 1.0 and 5.8 kWh/m².

The brighter stretch of the year lasts 6.1 months, from around Mar 17 to Sep 19. The brightest month is June, averaging about 5.6 kWh/m² (bright).

The dimmest month is December, down near 1.1 kWh/m² — roughly 81% less than the June peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJun 275.8 kWhDec 201.0 kWh
Solar energy (kWh/m²)Level
Jan1.3Dim
Feb2.1Moderate
Mar3.4Moderate
Apr4.7Bright
May5.2Bright
Jun5.6Bright
Jul5.6Bright
Aug4.8Bright
Sep3.6Moderate
Oct2.3Moderate
Nov1.4Dim
Dec1.0Dim

Where is Olten?

Olten sits at 47.4°N, 7.9°E, 406 m above sea level, in Switzerland. The nearest listed city is Aarau, 12 km away.

Bad SäckingenRheinfeldenMuttenzReinachSolothurnRiehenBaden

Topography around Olten

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Olten.

Within 3 km, the terrain around Olten has significant variations in elevation — a maximum elevation change of 423 m around an average of 480 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 819 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,417 m.

The land around Olten is covered by trees (58%) and artificial surfaces (21%) within 3 km, trees (53%) and grassland (25%) within 16 km, and trees (48%) and grassland (28%) within 80 km.

3 km
423 m
16 km
819 m
80 km
3,417 m
treesgrasslandcroplandartificial surfaceswater
Nearby: Aarau 12 km · Bad Säckingen 23 km · Rheinfelden 25 km · Muttenz 27 km · Reinach 29 km · Solothurn 32 km · Riehen 32 km · Baden 33 km

Switzerland travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / J
230 V · 50 Hz
Prices
≈ 112% of US
price level, 2025
GDP per capita
$114,769
2025
Happiness
7.0 / 10
World Happiness, 2025
Safe drinking water
97%
of population, 2024
Homicide rate
0.6
per 100k, 2023
Road deaths
2.2
per 100k/yr, 2019
Income group
High
World Bank
English
High
EF EPI 564
Religion
Roman Catholic 34%none 29%Protestant 23%other Christian 6%

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 Olten (47.35°, 7.9033°, elevation 406 m), 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).