September weather forecast
East Olympia, WA

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Weather in September

The first month of the autumn, September, is still a pleasant month in East Olympia, Washington, with an average temperature ranging between max 70.5°F (21.4°C) and min 47.7°F (8.7°C).

Temperature

September brings a slight decrease in the average high-temperature, shifting from a warm 78.6°F (25.9°C) in August to an agreeable 70.5°F (21.4°C). East Olympia records a significant temperature drop in September nights, lowering to an average of 47.7°F (8.7°C).

Humidity

The average relative humidity in September is 78%.

Rainfall

In East Olympia, in September, during 11.7 rainfall days, 1.81" (46mm) of precipitation is typically accumulated. Throughout the year, in East Olympia, there are 177.4 rainfall days, and 37.05" (941mm) of precipitation is accumulated.

Snowfall

April through October are months without snowfall in East Olympia.

Daylight

In East Olympia, the average length of the day in September is 12h and 32min.
On the first day of the month, sunrise is at 6:31 am and sunset at 7:50 pm. On the last day of September, in East Olympia, sunrise is at 7:09 am and sunset at 6:52 pm PDT.

Sunshine

In East Olympia, the average sunshine in September is 8.3h.

UV index

The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.
Note: A maximum high daily UV index of 4 during September translates into the following directions:
Exercise prevention - Protecting skin and eyes from harm is required. Minimize direct exposure to the Sun during midday when its radiation is at its peak. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for East Olympia in September?

In September, in East Olympia, the average high-temperature is 70.5°F (21.4°C), and the average low-temperature is 47.7°F (8.7°C).

What is the average humidity in September in East Olympia?

In East Olympia, Washington, the average relative humidity in September is 78%.

How much does it rain in East Olympia in September?

In September, in East Olympia, Washington, the rain falls for 11.7 days. Throughout September, 1.81" (46mm) of precipitation is accumulated.

When it does not snow in East Olympia?

April through October are months without snowfall in East Olympia, Washington.

What is the average length of the day in September in East Olympia?

In September, the average day length in East Olympia, Washington, is 12h and 32min.

When is the sunrise / sunset in September in East Olympia?

On the first day of September in East Olympia, sunrise is at 6:31 am and sunset at 7:50 pm. On the last day of the month, sunrise is at 7:09 am and sunset at 6:52 pm PDT.

How many hours of sunshine does East Olympia have in September?

In September, the average sunshine duration in East Olympia is 8.3h.

What is the UV index reading in September in East Olympia?

In East Olympia, Washington, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from unsafe 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
East Olympia, WA

Average temperature in September - East Olympia, WA
  • Average high temperature in September: 70.5°F

The warmest month (with the highest average high temperature) is August (78.6°F).
The month with the lowest average high temperature is December (43°F).

  • Average low temperature in September: 47.7°F

The month with the highest average low temperature is August (50.5°F).
The coldest month (with the lowest average low temperature) is December (33.4°F).

Average pressure in September
East Olympia, WA

Average pressure in September - East Olympia, WA
  • Average pressure in September: 30.02"Hg

The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is March (30.01"Hg).

Average wind speed in September
East Olympia, WA

Average wind speed in September - East Olympia, WA
  • Average wind speed in September: 3.8mph

The windiest months (with the highest average wind speed) are March and November (4.6mph).
The calmest month (with the lowest average wind speed) is September (3.8mph).

Average humidity in September
East Olympia, WA

Average humidity in September - East Olympia, WA
  • Average humidity in September: 78%

The months with the highest relative humidity are January, November and December (89%).
The month with the lowest relative humidity is July (71%).

Average rainfall in September
East Olympia, WA

Average rainfall in September - East Olympia, WA
  • Average rainfall in September: 1.81"

The wettest month (with the highest rainfall) is December (5.79").
The driest month (with the least rainfall) is July (0.39").

Average rainfall days in September
East Olympia, WA

Average rainfall days in September - East Olympia, WA
  • Average rainfall days in September: 11.7 days

The month with the highest number of rainy days is March (20.4 days).
The month with the least rainy days is August (5.5 days).

Average snowfall in September
East Olympia, WA

Average snowfall in September - East Olympia, WA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (2.32").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in September
East Olympia, WA

Average snowfall days in September - East Olympia, WA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (3.3 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
East Olympia, WA

Average daylight in September / Average sunshine in September - East Olympia, WA
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).

  • Average sunshine in September: 8h and 2min

The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is December (Average sunshine: 3h and 24min).

Average sunshine days in September
East Olympia, WA

Average sunshine days in September - East Olympia, WA
  • Average sunshine days in September: 16.1 days

The month with the most sunshine days is August (22.4 days).
The month with the least sunshine days is February (8.4 days).

Average UV index in September
East Olympia, WA

Average UV index in September - East Olympia, WA
  • Average UV index in September: 4

The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in September
East Olympia, WA

Average cloud cover in September - East Olympia, WA
  • Average cloud cover in September: 45

The months with the most cloud cover are January and December (Cloud cover 65).
The months with the least cloud cover are July and August (Cloud cover 35).

Average visibility in September
East Olympia, WA

Average visibility in September - East Olympia, WA
  • Average visibility in September: 4mi

The months with the highest visibility are June, July and August (5mi).
The months with the lowest visibility are January, February, March, April, May, September, October, November and December (4mi).

East Olympia, Washington, USA

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