September weather forecast
Greenhorn, OR

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Weather in September

September, the first month of the autumn in Greenhorn, is still a pleasant month, with an average temperature ranging between min 44.2°F (6.8°C) and max 71.2°F (21.8°C).

Temperature

A moderate decline in the average high-temperature is seen during September, decreasing from a warm 81°F (27.2°C) in August to a pleasant 71.2°F (21.8°C). Throughout the month of September, Greenhorn observes a dramatic downturn from the daytime peak temperatures, expecting an average low of 44.2°F (6.8°C).

Humidity

In September, the average relative humidity is 51%.

Rainfall

In September, in Greenhorn, the rain falls for 6.6 days. Throughout September, 0.55" (14mm) of precipitation is accumulated. Throughout the year, there are 127.7 rainfall days, and 17.09" (434mm) of precipitation is accumulated.

Snowfall

January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.08" (2mm) of snow. In Greenhorn, during the entire year, snow falls for 62.5 days and aggregates up to 39.17" (995mm) of snow.

Daylight

In Greenhorn, the average length of the day in September is 12h and 30min.
On the first day of September, sunrise is at 6:17 am and sunset at 7:30 pm. On the last day of the month, sunrise is at 6:51 am and sunset at 6:35 pm PDT.

Sunshine

In September, the average sunshine is 10.7h.

UV index

The average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for average individuals.
Note: The average daily UV index of 3 in September transforms into the following instructions:
Undertake precautions - Obligation exists to protect against skin and eye damage. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Be alert! Nearly double the UV rays from the Sun can be reflected by snow.

Frequently asked questions

What is the average September temperature?

The high-temperature during September is 71.2°F (21.8°C) and the low-temperature is 44.2°F (6.8°C). In August, the average heat index (a.k.a. 'real feel', 'apparent temperature'), which combines air temperature and relative humidity, is computed to be 80.6°F (27°C).

What is the average humidity in September in Greenhorn?

The average relative humidity in September is 51%.

How many days does it rain in September?

In Greenhorn, in September, during 6.6 rainfall days, 0.55" (14mm) of precipitation is typically accumulated.

When does it start snowing?

September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.08" (2mm) of snow.

How many hours of daylight does Greenhorn have in September?

In Greenhorn, the average day length in September is 12h and 30min.

When are sunrise and sunset in September?

On the first day of September, sunrise is at 6:17 am and sunset at 7:30 pm. On the last day of the month, sunrise is at 6:51 am and sunset at 6:35 pm PDT.

How long on average sun shines in September?

In September, the average sunshine duration is 10.7h.

What is the UV index intensity in September?

In September, the average daily maximum UV index is 3. A UV Index value of 3 to 5 symbolizes a moderate health threat from exposure to the Sun's UV radiation.
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
Greenhorn, OR

Average temperature in September - Greenhorn, OR
  • Average high temperature in September: 71.2°F

The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is December (33.4°F).

  • Average low temperature in September: 44.2°F

The month with the highest average low temperature is August (49.6°F).
The coldest month (with the lowest average low temperature) is December (19.6°F).

Average pressure in September
Greenhorn, OR

Average pressure in September - Greenhorn, OR
  • Average pressure in September: 29.97"Hg

The month with the highest atmospheric pressure is January (30.22"Hg).
The month with the lowest atmospheric pressure is August (29.93"Hg).

Average wind speed in September
Greenhorn, OR

Average wind speed in September - Greenhorn, OR
  • Average wind speed in September: 5mph

The windiest month (with the highest average wind speed) is April (6.2mph).
The calmest months (with the lowest average wind speed) are August and September (5mph).

Average humidity in September
Greenhorn, OR

Average humidity in September - Greenhorn, OR
  • Average humidity in September: 51%

The month with the highest relative humidity is February (85%).
The month with the lowest relative humidity is August (42%).

Average rainfall in September
Greenhorn, OR

Average rainfall in September - Greenhorn, OR
  • Average rainfall in September: 0.55"

The wettest month (with the highest rainfall) is February (2.28").
The driest month (with the least rainfall) is July (0.24").

Average rainfall days in September
Greenhorn, OR

Average rainfall days in September - Greenhorn, OR
  • Average rainfall days in September: 6.6 days

The month with the highest number of rainy days is March (17.3 days).
The month with the least rainy days is August (3.3 days).

Average snowfall in September
Greenhorn, OR

Average snowfall in September - Greenhorn, OR
  • Average snowfall in September: 0.08"

The month with the highest snowfall is February (10.31").
The months with the least snowfall are June, July and August (0").

Average snowfall days in September
Greenhorn, OR

Average snowfall days in September - Greenhorn, OR
  • Average snowfall days in September: 0.2 days

The month with the highest number of snowfall days is December (14.5 days).
The months with the least snowfall days are June, July and August (0 days).

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

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

The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).

  • Average sunshine in September: 10h and 4min

The month with the most sunshine is August (Average sunshine: 12h and 6min).
The months with the least sunshine are January and February (Average sunshine: 5h and 12min).

Average sunshine days in September
Greenhorn, OR

Average sunshine days in September - Greenhorn, OR
  • Average sunshine days in September: 21.8 days

The month with the most sunshine days is July (24.9 days).
The month with the least sunshine days is February (9 days).

Average UV index in September
Greenhorn, OR

Average UV index in September - Greenhorn, 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, October, November and December (UV index 2).

Average cloud cover in September
Greenhorn, OR

Average cloud cover in September - Greenhorn, OR
  • Average cloud cover in September: 17

The month with the most cloud cover is February (Cloud cover 49).
The months with the least cloud cover are July and August (Cloud cover 9).

Average visibility in September
Greenhorn, OR

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

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

Greenhorn, Oregon, USA

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