September weather forecast
Three Rivers, OR

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Weather in September

September, the first month of the autumn in Three Rivers, is still a pleasant month, with an average temperature ranging between min 45.5°F (7.5°C) and max 69.8°F (21°C).

Temperature

Transition into September subtly marks a drop in the average high-temperature, moderately moving from a moderately hot 78.3°F (25.7°C) in August to an agreeable 69.8°F (21°C). The significant decline in Three Rivers's temperature, from day to night, averages of 45.5°F (7.5°C) in September.

Humidity

In September, the average relative humidity in Three Rivers is 54%.

Rainfall

In Three Rivers, during September, the rain falls for 3.5 days and regularly aggregates up to 0.24" (6mm) of precipitation. Throughout the year, in Three Rivers, there are 42.7 rainfall days, and 4.8" (122mm) of precipitation is accumulated.

Snowfall

January through June, September through December are months with snowfall in Three Rivers, Oregon. September is the first month it typically snows. Throughout September, in the average 0.6 snowfall days, it receives 0.43" (11mm) of snow. In Three Rivers, during the entire year, snow falls for 40.2 days and aggregates up to 19.09" (485mm) of snow.

Daylight

In Three Rivers, Oregon, the average length of the day in September is 12h and 29min.
On the first day of the month, sunrise is at 6:30 am and sunset at 7:40 pm. On the last day of September, sunrise is at 7:03 am and sunset at 6:47 pm PDT.

Sunshine

In Three Rivers, the average sunshine in September is 11h.

UV index

In Three Rivers, Oregon, the average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for ordinary individuals.
Note: During September, 3 as the daily maximum UV index converts into the following advice:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck. Be cautious! The UV radiation from the Sun can be magnified almost twofold by snow reflection.
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Frequently asked questions

What are the temperatures in Three Rivers in September?

In Three Rivers, 69.8°F (21°C) is the average high-temperature and 45.5°F (7.5°C) is the average low-temperature during September.

What is the average humidity in September in Three Rivers?

In September, the average relative humidity in Three Rivers is 54%.

How many days does it rain in September in Three Rivers?

In September, in Three Rivers, the rain falls for 3.5 days. Throughout September, 0.24" (6mm) of precipitation is accumulated.

When does it start snowing in Three Rivers?

September is the first month it typically snows in Three Rivers, Oregon. Throughout September, in the average 0.6 snowfall days, it receives 0.43" (11mm) of snow.

How many hours of daylight does Three Rivers have in September?

The average day length in September in Three Rivers is 12h and 29min.

What time are sunrise and sunset in September in Three Rivers?

On the first day of September in Three Rivers, sunrise is at 6:30 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:03 am and sunset at 6:47 pm PDT.

How many hours of sunshine does Three Rivers have in September?

The average sunshine duration in September is 11h.

How high is the UV index in September in Three Rivers?

In Three Rivers, Oregon, the average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a medium health risk from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Three Rivers, OR

Average temperature in September - Three Rivers, OR
  • Average high temperature in September: 69.8°F

The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is December (34.5°F).

  • Average low temperature in September: 45.5°F

The month with the highest average low temperature is August (51.8°F).
The coldest month (with the lowest average low temperature) is December (23.7°F).

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Average pressure in September
Three Rivers, OR

Average pressure in September - Three Rivers, OR
  • Average pressure in September: 29.99"Hg

The month with the highest atmospheric pressure is January (30.18"Hg).
The month with the lowest atmospheric pressure is August (29.97"Hg).

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Average wind speed in September
Three Rivers, OR

Average wind speed in September - Three Rivers, OR
  • Average wind speed in September: 5.7mph

The windiest month (with the highest average wind speed) is March (7.6mph).
The calmest month (with the lowest average wind speed) is August (5.5mph).

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Average humidity in September
Three Rivers, OR

Average humidity in September - Three Rivers, OR
  • Average humidity in September: 54%

The month with the highest relative humidity is December (82%).
The month with the lowest relative humidity is July (46%).

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Average rainfall in September
Three Rivers, OR

Average rainfall in September - Three Rivers, OR
  • Average rainfall in September: 0.24"

The wettest month (with the highest rainfall) is February (0.71").
The driest month (with the least rainfall) is July (0.08").

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Average rainfall days in September
Three Rivers, OR

Average rainfall days in September - Three Rivers, OR
  • Average rainfall days in September: 3.5 days

The month with the highest number of rainy days is May (5.5 days).
The month with the least rainy days is February (2.3 days).

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Average snowfall in September
Three Rivers, OR

Average snowfall in September - Three Rivers, OR
  • Average snowfall in September: 0.43"

The month with the highest snowfall is February (4.61").
The months with the least snowfall are July and August (0").

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Average snowfall days in September
Three Rivers, OR

Average snowfall days in September - Three Rivers, OR
  • Average snowfall days in September: 0.6 days

The month with the highest number of snowfall days is December (7.4 days).
The months with the least snowfall days are July and August (0 days).

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Average daylight in September /
Average sunshine in September
Three Rivers, OR

Average daylight in September / Average sunshine in September - Three Rivers, OR
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).

  • Average sunshine in September: 11h and 0min

The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 30min).

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Average sunshine days in September
Three Rivers, OR

Average sunshine days in September - Three Rivers, OR
  • Average sunshine days in September: 24.4 days

The month with the most sunshine days is July (26.7 days).
The month with the least sunshine days is February (20.6 days).

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Average UV index in September
Three Rivers, OR

Average UV index in September - Three Rivers, OR
  • Average UV index in September: 3

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).

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Average cloud cover in September
Three Rivers, OR

Average cloud cover in September - Three Rivers, OR
  • Average cloud cover in September: 17

The month with the most cloud cover is December (Cloud cover 46).
The months with the least cloud cover are July and August (Cloud cover 9).

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Average visibility in September
Three Rivers, OR

Average visibility in September - Three Rivers, OR
  • Average visibility in September: 6mi

The months with the highest visibility are February, March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (5mi).

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Three Rivers, Oregon, USA

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