Temperatures in September
It's warm in September in Lake Oswego with an average temperature of 25°C. Temperatures this month range from a low of 21°C to a high of 29°C. At night, you can expect temperatures between 11°C and 16°C.
Max and Min Temperatures per Day
This chart shows the daily maximum and minimum temperatures in degrees Celsius for Lake Oswego in September. The red line indicates the max temperatures, and the blue line shows the minimums.
Start of September
The month of September starts in Lake Oswego with hot temperatures, averaging around 28°C during the day and nights close to 15°C. There’s little chance of precipitation. The weather is mostly sunny and dry.
Since temperatures can differ between day and night, it’s a good idea to dress in layers.
Mid-September
By mid-September, the average daytime temperature drops to around 24°C, with nights close to 14°C. During this part of the month, you can expect regular precipitation, but there’ll also be some sunny days.
End of September
By the end of September, the average daytime temperature in Lake Oswego will be around 24°C, with nights close to 13°C. There’s regular precipitation, but with a bit of luck, you’ll also get some dry and sunny days.
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Precipitation in September
In September, there is an average of 83 mm of precipitation, spread over 6 days. The wind speed is around 3 Bft, mostly coming from the West.
The average precipitation chance is 20% per day this month. Though that seems low, there are also a few days with a higher chance of precipitation.
Precipitation Chance
This chart shows the daily precipitation chance (in percentages) in September for Lake Oswego. 0% means it never rained on that day in the past 10 years, and 100% means it rained every day. All values in between represent the average chance of precipitation on that day.
Lake Oswego in September |
London | ||
|---|---|---|---|
 Average Temperature |
25°C | 20°C | |
 High Temp |
29°C | 22°C | |
| Low Temp |
21°C | 17°C | |
 Total Precipitation |
83 mm | 44 mm | |
| Rainy Days |
6 days | 8 days | |
August
UV index
The UV index is a maximum of 7 this month. That's a moderate to high value on the intensity scale of 1 to 11. Unprotected skin can burn within 15-25 minutes.
Is September a good time to visit Lake Oswego?
Want nice weather? Then September is a great time to be in Lake Oswego. You’ll have pleasant temperatures and not too much rain this month.
Temperature records for Lake Oswego in September
With 37°C, Lake Oswego hit the highest temperature in the last 10 years in September 2017. The lowest daytime temperature in this month was 10°C in 2019. The extreme night temperatures ranged from a low of 5°C to a high of 22°C.
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Daily Temperature in September in Lake Oswego
This chart shows the average daily temperatures, both day and night, for each day in September in Lake Oswego, measured in degrees Celsius. The red line represents the maximum temperatures, while the blue line shows the minimums. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, gives an overview of the average daily temperatures during this month.
Daily Precipitation in September in Lake Oswego
The chart below shows the average daily precipitation in September for Lake Oswego, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are shown at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that rain is more likely. But it’s still an average, so each day can be different. Based on historical weather data for September, you can expect around 6 days of rain in Lake Oswego.
Daily UV Index in September in Lake Oswego
This chart shows the average daily UV index in September in Lake Oswego, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Temperature in September in Lake Oswego Over the Years
This chart shows the average temperature in September in Lake Oswego, measured in degrees Celsius, over the past years.
Total Precipitation in September in Lake Oswego Over the Years
This chart shows the average precipitation in September in Lake Oswego, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail.
Daily climate in September for Lake Oswego
Click on a specific day in September for detailed info on the typical weather on that day in Lake Oswego. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in September in Lake Oswego
Have you been to Lake Oswego in September?
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Average Weather in Lake Oswego by Month
Click on a month below to see detailed weather info for Lake Oswego. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
Or check out the climate of Lake Oswego for all months at once
