September weather forecast
Cornelius, OR

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Cornelius, Oregon, with an average temperature varying between 73.9°F (23.3°C) and 51.4°F (10.8°C).

Temperature

Cornelius records a mild change in average high-temperature during September, easing from a warm 81.5°F (27.5°C) in August to a still moderately hot 73.9°F (23.3°C). Cornelius registers a significant reduction from the day's heat, with an average temperature drop to a fresh 51.4°F (10.8°C) in September.

Humidity

The average relative humidity in September is 70%.

Rainfall

In Cornelius, during September, the rain falls for 10.1 days and regularly aggregates up to 1.46" (37mm) of precipitation. Throughout the year, there are 173 rainfall days, and 29.49" (749mm) of precipitation is accumulated.

Snowfall

April through October are months without snowfall.

Daylight

The average length of the day in September is 12h and 31min.
On the first day of September, sunrise is at 6:34 am and sunset at 7:49 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 6:53 pm PDT.

Sunshine

In September, the average sunshine is 8.9h.

UV index

In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.
Note: In September, a daily UV index of 4 turns into the following recommendations:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.

Frequently asked questions

What are the temperatures in September?

During September, Cornelius experiences an average high-temperature of 73.9°F (23.3°C) and a low-temperature of 51.4°F (10.8°C). The average heat index (a.k.a. 'felt air temperature', 'real feel'), which factors the actual air temperature with the relative humidity, in August is estimated at 84.2°F (29°C).

What is the average humidity in September?

The average relative humidity in September is 70%.

How much does it rain in September?

In Cornelius, during September, the rain falls for 10.1 days and regularly aggregates up to 1.46" (37mm) of precipitation.

When it does not snow?

April through October are months without snowfall.

How many hours of daylight does Cornelius have in September?

In September, the average day length is 12h and 31min.

When is the sunrise / sunset in September?

In September, on the first day of the month, sunrise is at 6:34 am and sunset at 7:49 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 6:53 pm PDT.

How many hours of sunshine does Cornelius have in September?

In September, the average sunshine duration is 8.9h.

What is the UV index intensity in September?

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate vulnerability from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Cornelius, OR

Average temperature in September - Cornelius, OR
  • Average high temperature in September: 73.9°F

The warmest month (with the highest average high temperature) is August (81.5°F).
The month with the lowest average high temperature is December (43.9°F).

  • Average low temperature in September: 51.4°F

The month with the highest average low temperature is August (55.4°F).
The coldest month (with the lowest average low temperature) is December (34°F).

Average pressure in September
Cornelius, OR

Average pressure in September - Cornelius, OR
  • Average pressure in September: 30.01"Hg

The month with the highest atmospheric pressure is January (30.11"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).

Average wind speed in September
Cornelius, OR

Average wind speed in September - Cornelius, OR
  • Average wind speed in September: 4.3mph

The windiest month (with the highest average wind speed) is March (5mph).
The calmest months (with the lowest average wind speed) are June, August and September (4.3mph).

Average humidity in September
Cornelius, OR

Average humidity in September - Cornelius, OR
  • Average humidity in September: 70%

The months with the highest relative humidity are January, February, November and December (85%).
The month with the lowest relative humidity is August (64%).

Average rainfall in September
Cornelius, OR

Average rainfall in September - Cornelius, OR
  • Average rainfall in September: 1.46"

The wettest month (with the highest rainfall) is January (4.57").
The driest month (with the least rainfall) is August (0.31").

Average rainfall days in September
Cornelius, OR

Average rainfall days in September - Cornelius, OR
  • Average rainfall days in September: 10.1 days

The month with the highest number of rainy days is March (20.8 days).
The month with the least rainy days is August (4.4 days).

Average snowfall in September
Cornelius, OR

Average snowfall in September - Cornelius, OR
  • Average snowfall in September: 0"

The month with the highest snowfall is February (1.81").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in September
Cornelius, OR

Average snowfall days in September - Cornelius, OR
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (2.4 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).

Average daylight in September /
Average sunshine in September
Cornelius, OR

Average daylight in September / Average sunshine in September - Cornelius, 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: 8h and 5min

The month with the most sunshine is August (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 3h and 42min).

Average sunshine days in September
Cornelius, OR

Average sunshine days in September - Cornelius, OR
  • Average sunshine days in September: 17.2 days

The month with the most sunshine days is July (24.4 days).
The month with the least sunshine days is March (8.5 days).

Average UV index in September
Cornelius, OR

Average UV index in September - Cornelius, 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
Cornelius, OR

Average cloud cover in September - Cornelius, OR
  • Average cloud cover in September: 36

The month with the most cloud cover is February (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 25).

Average visibility in September
Cornelius, OR

Average visibility in September - Cornelius, OR
  • Average visibility in September: 6mi

The months with the highest visibility are July, August and September (6mi).
The months with the lowest visibility are January and February (4mi).

Cornelius, Oregon, USA

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