Onex in Fall
In fall (September, October and November), Onex sees average daytime highs around 14°C and overnight lows near 6°C, with 384 mm of precipitation over about 38 wet days across the season. It is the 3rd-warmest season and the 2nd-wettest season.
Over the season highs ease from about 21°C in early September to 6°C by late November. The sky is clear or mostly clear about 24% of the time across fall, and the air most often feels dry.
Fall is Onex's 2nd-best season to visit on our travel score. For the whole year in context, see Onex's year-round climate.
- Avg daytime high
- 14°C
- 3rd-warmest season
- Avg overnight low
- 6°C
- Precipitation
- 384 mm
- 38 wet days
- Avg wind
- 6 km/h
- Travel score
- 3.7
- 2nd-best season
- Months
- Sep · Oct · Nov
Temperature in Onex in Fall
Over the season highs ease from about 21°C in early September to 6°C by late November.
A typical fall day in Onex reaches about 14°C and drops to 6°C overnight. The warmest of the three months is September, the coolest November.
How fall really feels in Onex
Once humidity and wind are folded in, fall brings about 0 days that feel above 32°C and 17 that feel at or below 0°C.
The story in fall is cold — wind chill drags the overnight "feels like" below the raw low.
Onex weather by month
How the three fall months (September, October and November) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 5° / -2° | 126 | 12.8 | 7.3 | 8.8 | 0.0 |
| Feb | 6° / -1° | 107 | 11.2 | 6.6 | 10 | 0.4 |
| Mar | 10° / 2° | 119 | 12.5 | 4.4 | 11.6 | 2.4 |
| Apr | 14° / 5° | 115 | 13.4 | 2.2 | 13.3 | 3.7 |
| May | 18° / 9° | 142 | 15.9 | 0.3 | 14.7 | 4.9 |
| Jun | 21° / 12° | 130 | 14.4 | 0 | 15.5 | 5.9 |
| Jul | 24° / 14° | 131 | 13.5 | 0 | 15.2 | 6.6 |
| Aug | 23° / 13° | 129 | 13.2 | 0 | 14 | 6.6 |
| Sep | 19° / 10° | 121 | 12 | 0 | 12.3 | 5.7 |
| Oct | 14° / 6° | 128 | 12.9 | 0.5 | 10.7 | 3.9 |
| Nov | 9° / 2° | 136 | 13.2 | 3.6 | 9.2 | 1.4 |
| Dec | 5° / -1° | 147 | 13.5 | 6.8 | 8.5 | 0.1 |
Cloud cover in Fall
The sky is clear or mostly clear about 24% of the time across fall.
Chance of precipitation in Fall
Onex gets around 384 mm of rain and snow over 38 wet days across fall. The line is the day-by-day chance of measurable precipitation.
Humidity in Fall
Most of fall feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Fall
Winds average 6 km/h across fall.
Sunrise & sunset in Fall
Daylight runs from about 13 h 12 min in early September to 8 h 42 min by late November. The lit band spans sunrise to sunset each day.
Solar energy in Fall
Average shortwave solar energy reaching the ground each day across fall, about 2.6 kWh/m².
Is fall a good time to visit Onex?
Our two travel scores rate fall for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
fall is a weaker month for outdoor sightseeing in Onex.
What to pack for Onex in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, Onex sees daytime highs around 14°C and nights near 6°C. Pack a warm layer. Worth having: rain gear. About 38 days see rain.
UV index in Onex in Fall
Clear-sky midday UV across fall averages around 3 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Onex peaks around July 15 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 at about 1 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 2 | 4 | 5 | 7 | 7 | 9 | 7 | 5 | 3 | 2 | 1 |
| Level | Low | Moderate | Moderate | Moderate | High | Very high | Very high | High | Moderate | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 2 | Moderate |
| Mar | 4 | Moderate |
| Apr | 5 | Moderate |
| May | 7 | High |
| Jun | 7 | Very high |
| Jul | 9 | Very high |
| Aug | 7 | High |
| Sep | 5 | Moderate |
| Oct | 3 | Moderate |
| Nov | 2 | Low |
| Dec | 1 | Low |
Air quality in Onex in Fall
Average fine-particle pollution (PM2.5) through the year — so you can see where fall falls, not just the annual average.
Air quality in Onex is worst in April — around 15 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 13 | 12 | 15 | 15 | 13 | 15 | 11 | 11 | 11 | 10 | 10 | 11 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 13 | Moderate |
| Feb | 12 | Moderate |
| Mar | 15 | Moderate |
| Apr | 15 | Moderate |
| May | 13 | Moderate |
| Jun | 15 | Moderate |
| Jul | 11 | Good |
| Aug | 11 | Good |
| Sep | 11 | Good |
| Oct | 10 | Good |
| Nov | 10 | Good |
| Dec | 11 | Good |
Where is Onex?
Onex sits at 46.2°N, 6.1°E, 426 m above sea level, in Switzerland. The nearest listed city is Lancy, 1.0 km away.
Topography around Onex
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Onex.
Within 3 km, the terrain around Onex has only modest variations in elevation — a maximum elevation change of 132 m around an average of 411 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,383 m; within 80 km, extreme variations in elevation — a maximum elevation change of 4,606 m.
The land around Onex is covered by artificial surfaces (37%) and trees (36%) within 3 km, trees (43%) and grassland (24%) within 16 km, and trees (53%) and grassland (29%) within 80 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
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 Onex (46.184°, 6.1024°, elevation 426 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.