September weather - Autumn 2023

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

The iconic Painted Hills in the famous John Day Fossil Beds National Monument, Oregon

Weather in September

With the commencement of September, the weather starts to transition into fall. Although the temperature drop is nominal, the observable difference is the increase in rainfall to 0.55". The presence of early fall foliage starts to draw leaf-peepers. However, the wind picks up speed, and it mostly remains a mix of summer and fall. September in John Day, Oregon is known for its sunny days that lean into chiller nights.

Temperature

Transition from August to September is accompanied by a temperature drop, with average high-temperatures decreasing from a warm 81°F to a pleasant 71.2°F. September nights in John Day are characterized by a significant departure from the daytime highs, dropping to an average temperature of 44.2°F.

Humidity

In John Day, Oregon, the average relative humidity in September is 51%.

Rainfall

In John Day, in September, during 6.6 rainfall days, 0.55" of precipitation is typically accumulated. In John Day, during the entire year, the rain falls for 127.7 days and collects up to 17.09" of precipitation.

Snowfall

Months with snowfall in John Day are January through May, September through December. September is the first month it typically snows in John Day, Oregon. Throughout September, in the average 0.2 snowfall days, it receives 0.08" of snow. Throughout the year, there are 62.5 snowfall days, and 39.17" of snow is accumulated.

Daylight

In September, the average length of the day in John Day is 12h and 30min.
On the first day of the month, sunrise is at 6:18 am and sunset at 7:32 pm. On the last day of September, in John Day, sunrise is at 6:52 am and sunset at 6:39 pm PDT.

Sunshine

The average sunshine in September in John Day is 10.7h.

UV index

In John Day, the average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the average person.
Note: An average maximum UV index of 3 in September leads to these recommendations:
Act with care - Obligation to protect against skin and eye damage is highlighted. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim. Heed this! Snow reflection can almost augment the UV radiation of the sun by double.

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FAQ

What is the temperature in September in John Day?

The high-temperature during September is 71.2°F and the low-temperature is 44.2°F. In August, the average heat index (a.k.a. 'felt air temperature', 'feels like'), which combines air temperature and relative humidity, is evaluated at 80.6°F.

What is the average humidity in September in John Day?

In John Day, the average relative humidity in September is 51%.

How much does it rain in John Day in September?

In John Day, Oregon, in September, during 6.6 rainfall days, 0.55" of precipitation is typically accumulated.

When does it start to snow in John Day?

September is the first month it typically snows in John Day. Throughout September, in the average 0.2 snowfall days, it receives 0.08" of snow.

How many hours of daylight does John Day have in September?

In John Day, Oregon, the average day length in September is 12h and 30min.

What time are sunrise and sunset in September in John Day?

On the first day of September in John Day, sunrise is at 6:18 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:52 am and sunset at 6:39 pm PDT.

How many hours of sunshine does John Day have in September?

In September, the average sunshine duration in John Day is 10.7h.

What is the UV index intensity in September in John Day?

In John Day, Oregon, the average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a medium hazard to health from unsafe exposure to Sun's UV rays.

Today

Tomorrow

Long-term

Year J F M A M J J A September O N D

Aug

September

Oct

Average high temperature

81°F

71.2°F

56.3°F

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

6.2mph

5.5mph

6mph

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average snowfall

Average snowfall days

Average daylight

Average sunshine

Average sunshine days

24.8

21.8

18.1

Average UV index

Average cloud cover

17%

29%

Average visibility

6mi

Average temperature in September
John Day, 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).

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Average pressure in September
John Day, 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).

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Average wind speed in September
John Day, 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).

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Average humidity in September
John Day, 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%).

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Average rainfall in September
John Day, 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").

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Average rainfall days in September
John Day, 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).

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Average snowfall in September
John Day, 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").

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Average snowfall days in September
John Day, 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).

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Average daylight in September /
Average sunshine in September
John Day, 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).

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Average sunshine days in September
John Day, 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).

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Average UV index in September
John Day, 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).

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Average cloud cover in September
John Day, 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).

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Average visibility in September
John Day, 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).

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September weather forecast
John Day, OR

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