Lake Oswego in Fall
In fall (September, October and November), Lake Oswego sees average daytime highs around 63°F and overnight lows near 46°F, with 12.7 in of precipitation over about 35 wet days across the season. It is the 2nd-warmest season and the 3rd-wettest season.
Over the season highs ease from about 78°F in early September to 48°F by late November. The sky is clear or mostly clear about 31% of the time across fall, and the air most often feels dry.
Fall is Lake Oswego's 2nd-best season to visit on our travel score. For the whole year in context, see Lake Oswego's year-round climate.
- Avg daytime high
- 63°F
- 2nd-warmest season
- Avg overnight low
- 46°F
- Precipitation
- 12.7 in
- 35 wet days
- Avg wind
- 5 mph
- Travel score
- 5.0
- 2nd-best season
- Months
- Sep · Oct · Nov
Temperature in Lake Oswego in Fall
Over the season highs ease from about 78°F in early September to 48°F by late November.
A typical fall day in Lake Oswego reaches about 63°F and drops to 46°F overnight. The warmest of the three months is September, the coolest November.
How fall really feels in Lake Oswego
Once humidity and wind are folded in, fall brings about 0 days that feel above 90°F and 0 that feel at or below 32°F.
fall sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Lake Oswego 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 (°F) | Rainfall (inches) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 47° / 36° | 6.6 | 17.3 | 1.8 | 8.9 | 1.2 |
| Feb | 50° / 37° | 5.0 | 14.8 | 1.5 | 10.1 | 2.0 |
| Mar | 55° / 39° | 5.7 | 17.5 | 0.7 | 11.6 | 2.8 |
| Apr | 60° / 42° | 4.5 | 16.1 | 0 | 13.2 | 4.0 |
| May | 67° / 48° | 2.8 | 11.1 | 0 | 14.7 | 5.9 |
| Jun | 72° / 52° | 1.7 | 7.6 | 0 | 15.4 | 7.0 |
| Jul | 80° / 56° | 0.5 | 2.3 | 0 | 15.1 | 8.0 |
| Aug | 81° / 56° | 0.6 | 2.6 | 0 | 13.9 | 7.9 |
| Sep | 75° / 52° | 1.6 | 6.2 | 0 | 12.3 | 7.7 |
| Oct | 63° / 46° | 4.2 | 11.9 | 0 | 10.7 | 5.2 |
| Nov | 52° / 40° | 6.9 | 17.3 | 0.4 | 9.3 | 2.2 |
| Dec | 46° / 36° | 7.6 | 18 | 2.2 | 8.6 | 0.9 |
Cloud cover in Fall
The sky is clear or mostly clear about 31% of the time across fall.
Chance of precipitation in Fall
Lake Oswego gets around 12.7 in of rain and snow over 35 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 5 mph 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 2.8 kWh/m².
Hazard calendar for Lake Oswego
In fall, Lake Oswego overlaps its rainy season season. The full year is below, with each hazard's peak months called out.
Lake Oswego's rainy season runs October–April, when most of the year's rain falls.
Is fall a good time to visit Lake Oswego?
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 reasonable time to visit Lake Oswego for sightseeing.
What to pack for Lake Oswego in Fall
From fall's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In fall, Lake Oswego sees daytime highs around 63°F and nights near 46°F. Pack a warm layer and rain gear. Worth having: light clothes. About 35 days see rain.
UV index in Lake Oswego in Fall
Clear-sky midday UV across fall averages around 3. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Lake Oswego peaks around July 17 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 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 | 8 | 7 | 8 | 7 | 4 | 3 | 1 | 1 |
| Level | Low | Low | Moderate | Moderate | Very high | High | Very high | High | Moderate | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 2 | Low |
| Mar | 4 | Moderate |
| Apr | 5 | Moderate |
| May | 8 | Very high |
| Jun | 7 | High |
| Jul | 8 | Very high |
| Aug | 7 | High |
| Sep | 4 | Moderate |
| Oct | 3 | Moderate |
| Nov | 1 | Low |
| Dec | 1 | Low |
Air quality in Lake Oswego 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 Lake Oswego is worst in September — around 22 µg/m³ PM2.5 (moderate), about 3.0× the cleanest month (January, 7 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 7 | 9 | 11 | 11 | 10 | 9 | 8 | 13 | 22 | 14 | 9 | 7 |
| Level | Good | Good | Good | Good | Good | Good | Good | Moderate | Moderate | Moderate | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 7 | Good |
| Feb | 9 | Good |
| Mar | 11 | Good |
| Apr | 11 | Good |
| May | 10 | Good |
| Jun | 9 | Good |
| Jul | 8 | Good |
| Aug | 13 | Moderate |
| Sep | 22 | Moderate |
| Oct | 14 | Moderate |
| Nov | 9 | Good |
| Dec | 7 | Good |
Where is Lake Oswego?
Lake Oswego sits at 45.4°N, 122.7°W, 180 ft above sea level, in United States. The nearest listed city is Oak Grove, 1.2 mi away.
Topography around Lake Oswego
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Lake Oswego.
Within 2 miles, the terrain around Lake Oswego has only modest variations in elevation — a maximum elevation change of 758 ft around an average of 272 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,306 ft; within 50 miles, extreme variations in elevation — a maximum elevation change of 11,093 ft.
The land around Lake Oswego is covered by trees (76%) within 2 miles, trees (63%) and artificial surfaces (21%) within 10 miles, and trees (76%) within 50 miles.
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
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 Lake Oswego (45.4207°, -122.6706°, elevation 180 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.