Lake Oswego (OR) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Lake Oswego.
Climate overview of Lake Oswego
Lake Oswego, Oregon, United States of America, sees big temperature differences between seasons, with July peaking at 28°C (82°F) and December dropping to 8°C (46°F).
The city receives considerable rain/snowfall, with around 1155 mm (45 in) annually. December is the wettest month. It has a distinct dry season from July to August, with warm summers and cold winters. The sunniest month is July, with 11.1 hours of sunshine per day on average.
Lake Oswego Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Lake Oswego - and find the best time to visit.
Monthly Temperature in Lake Oswego
Visitors to Lake Oswego can expect significant temperature changes throughout the year. Typically, average maximum daytime temperatures range from a comfortable 28°C (82°F) in July to a chilly 8°C (46°F) in the coolest month, December.
Nights vary from 14°C (57°F) in July to around 2°C (36°F) during the colder months.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Lake Oswego
Lake Oswego is known for its substantial rain/snowfall, with annual precipitation reaching 1155 mm (45 in). The climate in Lake Oswego shows significant variation throughout the year. Expect heavy rainfall in December, the wettest month, with an average of 193 mm (7.6 in) of precipitation over 21 rainy days.
In contrast, the driest month July offers drier and sunnier days, with around 11 mm (0.4 in) of rainfall over 4 rainy days. For more details, please visit our Lake Oswego Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in Lake Oswego
For those who appreciate different seasons, Lake Oswego serves as an ideal destination. Expect longer, more sun-filled days in July with an average of 11.1 hours of sunshine daily, and embrace the darker days in December, offering only 2.1 hours of daily sunlight.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Humidity in Lake Oswego by Month
The relative humidity is high throughout the year in Lake Oswego.
The city experiences its highest humidity in December, reaching 83%. In July, the humidity drops to its lowest level at 63%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Wind Speed in Lake Oswego
The mean wind speed over the year ranges from 2 m/s (4 knots) in September and October to 4 m/s (8 knots) in January. What does this mean?
The mean monthly wind speed over the year (meters per second)
Best Time to Visit Lake Oswego
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: May, June, July, August and September
- Warmest weather: July and August
- Most sunshine: July
- Fewest rainy days: July and August
- Wettest months: January, February, March, October, November and December, when rainfall is highest.
- Seasonal pattern: A distinct dry season from July to August, with warm summers and cold winters
Frequently asked questions about the climate in Lake Oswego
What is the best time to visit Lake Oswego?
May, June, July, August and September typically offer the most optimal weather in Lake Oswego. In contrast, January, March, November and December tend to have less optimal conditions. Lake Oswego has a distinct dry season from July to August, with warm summers and cold winters.
What temperatures can I expect in Lake Oswego?
Daytime highs range from 8°C (46°F) in December to 28°C (82°F) in July. Nighttime lows range from 2°C (36°F) to 14°C (57°F). Temperatures vary considerably through the year.
How much rain does Lake Oswego get?
Annual rainfall is around 1155 mm (45 in). December is the wettest month with 193 mm (7.6 in), while July is the driest with 11 mm (0.4 in).
How sunny is Lake Oswego?
Lake Oswego receives around 2,341 hours of sunshine per year. July is the sunniest month with 332 hours, while December is the cloudiest with just 64 hours. Overall, Lake Oswego enjoys abundant sunshine.
Lake Oswego 3-Day Forecast
Lake Oswego (OR) 3-Day Forecast
Lake Oswego on the map
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