Lake Oswego Weather in September

Lake Oswego in September averages 25°C (77°F) during the day and 11°C (52°F) at night. This is part of the summer season. Some rainfall is to be expected.

Rainfall in Lake Oswego in September

Historically, the month has about 9 days of rain, averaging 43 mm (1.7 in) in total. The rainfall pattern this month is fairly balanced. Showers tend to be moderate rather than extreme.

Temperature in Lake Oswego in September

September is a good time to be in Lake Oswego. Days are perfect, reaching 25°C (77°F), with nights around 11°C (52°F). September is part of summer. This kind of day-to-night contrast is typical for this time of year. With overnight lows of 11°C (52°F), evenings can feel noticeably cooler than the daytime. An extra layer is a good idea, though the cool air makes for a good night's sleep.

Sunshine in Lake Oswego in September

The city usually sees around 236 hours of sunlight, indicating many sunny days — a great month for sightseeing.

Wind Speed in Lake Oswego in September

Average wind conditions reach 2 m/s (4 knots) in September. This creates comfortable weather with light winds that gently move vegetation. Keep in mind this is an average. Daily conditions range from near-calm to more noticeable wind.

If you favor pleasant temperatures and minimal rainfall, September is one of the best months to visit Lake Oswego.

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• January
• February
• March
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• May
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• October
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• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Lake Oswego's climate page.

Lake Oswego Temperature in September

Min Temperature 11°C (52°F)  

Max Temperature 25°C (77°F)  

Chance of Rain 30%  

Precipitation 43 mm (1.7 in)  

Rainy days 9 days  

Humidity 69% *  

Windspeed 2 m/s (4 knots) *  

Sunshine 236 hours *  

Percentage Sunshine *  

* Data from: Portland, the United States of America (20 KM, 12 Miles).

What to Wear in Lake Oswego in September

For Lake Oswego in September, you'll want flexible clothing. It's wise to pack cotton shirts, comfortable shorts, and a pair of jeans for cooler evenings. A light sweater or jacket is useful for air-conditioned spaces (like buses) or unexpected cool moments. Rain is likely on several days, so bring a good rain jacket. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.

What To Do in Lake Oswego in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

10/10

Cycling

10/10

Walking

10/10

Barbeque

9/10

Camping

10/10

Outdoor sports

10/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Lake Oswego's climate page.

More climate data for Lake Oswego

Temperature Rainfall Sunshine Humidity Wind Speed

See the full Lake Oswego climate overview or explore weather in the United States of America.