Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
As September commences in Lake Oswego, the average high-temperature subtly reduces, transitioning from a moderately hot 81.7°F (27.6°C) in August to a still warm 74.1°F (23.4°C). During the nights in September, Lake Oswego records a pronounced shift from the daytime warmth, with a consistent average temperature of 51.1°F (10.6°C).Humidity
The average relative humidity in September is 69%.Rainfall
In Lake Oswego, during September, the rain falls for 10.4 days and regularly aggregates up to 1.69" (43mm) of precipitation. Throughout the year, in Lake Oswego, there are 172.2 rainfall days, and 31.3" (795mm) of precipitation is accumulated.Snowfall
In Lake Oswego, Oregon, snow does not fall in April through October.Daylight
In Lake Oswego, the average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:33 am and sunset at 7:47 pm. On the last day of September, sunrise is at 7:08 am and sunset at 6:52 pm PDT.
Sunshine
In Lake Oswego, the average sunshine in September is 9.3h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for ordinary individuals.Note: The UV index of 4 during September leads to these advisories:
Guard yourself - Precautionary measures against sun damage are advocated. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat.
Frequently asked questions
What are September temperatures in Lake Oswego?
What is the average humidity in September in Lake Oswego?
How many days does it rain in September in Lake Oswego?
When it does not snow in Lake Oswego?
What is the average length of the day in September in Lake Oswego?
What time are sunrise and sunset in September in Lake Oswego?
How long on average sun shines in September in Lake Oswego?
What is the UV index intensity in September in Lake Oswego?
Average temperature in September
Lake Oswego, OR
- Average high temperature in September: 74.1°F
The warmest month (with the highest average high temperature) is August (81.7°F).
The month with the lowest average high temperature is December (44.4°F).
- Average low temperature in September: 51.1°F
The month with the highest average low temperature is August (54.5°F).
The coldest month (with the lowest average low temperature) is December (34.7°F).
Average pressure in September
Lake Oswego, OR
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed in September
Lake Oswego, OR
- Average wind speed in September: 3.9mph
The windiest month (with the highest average wind speed) is January (6mph).
The calmest month (with the lowest average wind speed) is August (3.7mph).
Average humidity in September
Lake Oswego, OR
- Average humidity in September: 69%
The month with the highest relative humidity is February (84%).
The month with the lowest relative humidity is August (63%).
Average rainfall in September
Lake Oswego, OR
- Average rainfall in September: 1.69"
The wettest month (with the highest rainfall) is December (4.57").
The driest month (with the least rainfall) is July (0.31").
Average rainfall days in September
Lake Oswego, OR
- Average rainfall days in September: 10.4 days
The month with the highest number of rainy days is March (20.4 days).
The month with the least rainy days is July (4.8 days).
Average snowfall in September
Lake Oswego, OR
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.46").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Lake Oswego, OR
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Lake Oswego, OR
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is August (Average sunshine: 11h and 0min).
The month with the least sunshine is February (Average sunshine: 4h and 12min).
Average sunshine days in September
Lake Oswego, OR
- Average sunshine days in September: 17.5 days
The month with the most sunshine days is July (23.9 days).
The month with the least sunshine days is February (8.3 days).
Average UV index in September
Lake Oswego, OR
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Lake Oswego, OR
- Average cloud cover in September: 33
The month with the most cloud cover is February (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 22).
Average visibility in September
Lake Oswego, OR
- Average visibility in September: 6mi
The months with the highest visibility are July, August, September and October (6mi).
The months with the lowest visibility are January, February, March, April, May, June, November and December (5mi).
Lake Oswego, Oregon, USA
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