Ottawa South in Fall
In fall (September, October and November), Ottawa South sees average daytime highs around 12°C and overnight lows near 4°C, with 277 mm of precipitation over about 34 wet days across the season. It is the 2nd-warmest season and the 2nd-wettest season.
Over the season highs ease from about 23°C in early September to 2°C by late November. The sky is clear or mostly clear about 20% of the time across fall, and the air most often feels dry.
Fall is Ottawa South's 2nd-best season to visit on our travel score. For the whole year in context, see Ottawa South's year-round climate.
- Avg daytime high
- 12°C
- 2nd-warmest season
- Avg overnight low
- 4°C
- Precipitation
- 277 mm
- 34 wet days
- Avg wind
- 11 km/h
- Travel score
- 3.2
- 2nd-best season
- Months
- Sep · Oct · Nov
Temperature in Ottawa South in Fall
Over the season highs ease from about 23°C in early September to 2°C by late November.
A typical fall day in Ottawa South reaches about 12°C and drops to 4°C overnight. The warmest of the three months is September, the coolest November.
How fall really feels in Ottawa South
Once humidity and wind are folded in, fall brings about 0 days that feel above 32°C and 42 that feel at or below 0°C.
The story in fall is cold — wind chill drags the overnight "feels like" below the raw low.
Ottawa South 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 | -6° / -15° | 73 | 10.5 | 9.7 | 8.9 | 0.0 |
| Feb | -4° / -14° | 57 | 8.7 | 8.1 | 10.1 | 0.0 |
| Mar | 2° / -8° | 73 | 9.9 | 6.8 | 11.6 | 0.0 |
| Apr | 11° / 1° | 90 | 11.1 | 3.2 | 13.2 | 2.6 |
| May | 19° / 7° | 88 | 11.4 | 0.2 | 14.7 | 5.6 |
| Jun | 23° / 12° | 99 | 11.7 | 0 | 15.4 | 6.4 |
| Jul | 26° / 15° | 98 | 12.4 | 0 | 15.1 | 6.4 |
| Aug | 24° / 14° | 90 | 11.1 | 0 | 13.9 | 6.7 |
| Sep | 20° / 10° | 95 | 10.4 | 0 | 12.3 | 6.2 |
| Oct | 12° / 4° | 99 | 12.3 | 0.7 | 10.7 | 3.1 |
| Nov | 5° / -2° | 83 | 11.4 | 4.4 | 9.3 | 0.4 |
| Dec | -2° / -9° | 79 | 11.4 | 9.1 | 8.6 | 0.0 |
Cloud cover in Fall
The sky is clear or mostly clear about 20% of the time across fall.
Chance of precipitation in Fall
Ottawa South gets around 277 mm of rain and snow over 34 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 11 km/h across fall.
Sunrise & sunset in Fall
Daylight runs from about 13 h 06 min in early September to 8 h 48 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 Ottawa South?
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 Ottawa South.
What to pack for Ottawa South in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, Ottawa South sees daytime highs around 12°C and nights near 4°C. Pack a warm layer and a heavy coat. Worth having: rain gear. About 34 days see rain.
UV index in Ottawa South 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 Ottawa South peaks around July 13 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. 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 7 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 2 | 3 | 4 | 6 | 7 | 8 | 5 | 5 | 3 | 2 | 1 |
| Level | Low | Low | Moderate | Moderate | High | High | Very high | Moderate | High | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 2 | Low |
| Mar | 3 | Moderate |
| Apr | 4 | Moderate |
| May | 6 | High |
| Jun | 7 | High |
| Jul | 8 | Very high |
| Aug | 5 | Moderate |
| Sep | 5 | High |
| Oct | 3 | Moderate |
| Nov | 2 | Low |
| Dec | 1 | Low |
Where is Ottawa South?
Ottawa South sits at 45.4°N, 75.7°W, 62 m above sea level, in Canada. The nearest listed city is Ottawa, 2.0 km away.
Topography around Ottawa South
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Ottawa South.
Within 3 km, the terrain around Ottawa South has only modest variations in elevation — a maximum elevation change of 58 m around an average of 75 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 256 m; within 80 km, significant variations in elevation — a maximum elevation change of 585 m.
The land around Ottawa South is covered by artificial surfaces (47%) and trees (29%) within 3 km, trees (40%) and artificial surfaces (25%) within 16 km, and trees (62%) and cropland (21%) within 80 km.
Canada travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 83% of US
- price level, 2025
- GDP per capita
- $55,698
- 2025
- Happiness
- 6.7 / 10
- World Happiness, 2025
- Safe drinking water
- 97%
- of population, 2024
- Homicide rate
- 2
- per 100k, 2023
- Road deaths
- 5.3
- per 100k/yr, 2019
- Income group
- High
- World Bank
- 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 Ottawa South (45.3921°, -75.6873°, elevation 62 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.