Annual mean 12°C · wettest around January · prevailing wind S
Warmest
25.5 °C
Coldest
6.0 °C
Wettest
21%
Windiest
4.2 m/s
Prevailing
S
3.1 m/s average
When this place is good five ratings · thirty-six ten-day sections · click a cell to read it
never good
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Every reading
bars actual · line feels-like, °Cchance of rain, %wind speed, m/ssky covered, %
The average temperature in Lake Oswego over the whole year is 12°C. August is the hottest month, with highs of about 27°C; February is the coldest, with lows of about 4°C. The rainy (wet) season in Lake Oswego runs from October to April, peaking in January with a 25% chance of rain on a given day. The dry season is May to September; July is the driest month, at 2%. Winds in Lake Oswego are highest in January, averaging 3.4 m/s (12 km/h), and lightest in September, at 1.9 m/s (7 km/h). The prevailing wind is from the S. The clearest skies in Lake Oswego come in July, when the sky is typically 27% covered; December is the cloudiest month, at 73%.
Month by month Lake Oswego climate by month: average temperatures year round · click a month to read it
Month
High
Low
Feels like
Chance of rain
Cloud
Wind
Being outside
Sun
Walking
January
7°C
4°C
3°C
25%
72%
3.4 m/s
0
0
25
February
7°C
4°C
3°C
22%
72%
2.9 m/s
0
0
30
March
11°C
5°C
7°C
21%
64%
2.7 m/s
5
0
52
April
15°C
7°C
11°C
16%
58%
2.6 m/s
22
1
76
May
19°C
11°C
16°C
11%
53%
2.2 m/s
56
7
84
June
23°C
14°C
19°C
8%
45%
2.3 m/s
75
18
74
July
27°C
15°C
23°C
2%
27%
2.3 m/s
84
40
53
August
27°C
15°C
24°C
3%
30%
2.0 m/s
79
45
47
September
22°C
13°C
20°C
8%
45%
1.9 m/s
85
18
74
October
16°C
9°C
13°C
17%
54%
2.1 m/s
42
2
83
November
10°C
6°C
7°C
24%
69%
2.7 m/s
5
0
51
December
7°C
4°C
3°C
24%
73%
3.1 m/s
0
0
23
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short Lake Oswego weather by season
Year round, Lake Oswego has days of about 7°C at their warmest in January, its coolest month, and 27°C in August, its warmest; the coolest hours of the day run from 4°C to 15°C through the year, and the average temperature over the year is 12°C around the clock. Rain is most likely around January and least likely around July. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
Lake Oswego weather in winterDecember to February
High 7°CLow 4°CRain 23%
Winter in Lake Oswego has typical daily highs of about 7°C and lows of about 4°C, with a 23% chance of rain on a given day.
Lake Oswego weather in springMarch to May
High 15°CLow 8°CRain 16%
Spring in Lake Oswego has typical daily highs of about 15°C and lows of about 8°C, with a 16% chance of rain on a given day.
Lake Oswego weather in summerJune to August
High 26°CLow 15°CRain 4%
Summer in Lake Oswego has typical daily highs of about 26°C and lows of about 15°C, with a 4% chance of rain on a given day.
Lake Oswego weather in autumnSeptember to November
High 16°CLow 9°CRain 16%
Autumn in Lake Oswego has typical daily highs of about 16°C and lows of about 9°C, with a 16% chance of rain on a given day.
When is the rainy season in Lake Oswego?
The rainy (wet) season in Lake Oswego runs from October to April, peaking in January with a 25% chance of rain on a given day. The dry season is May to September; July is the driest month, at 2%.
What time of year is Lake Oswego windiest?
Winds in Lake Oswego are highest in January, averaging 3.4 m/s (12 km/h), and lightest in September, at 1.9 m/s (7 km/h). The prevailing wind is from the S.
What is the average temperature in Lake Oswego year round?
The average temperature in Lake Oswego over the whole year is 12°C. August is the hottest month, with highs of about 27°C; February is the coldest, with lows of about 4°C.