Olympia
Washington, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Olympia, WA

The calm Capitol Lake overlooking the Washington State Capitol building in Olympia, Washington
The calm Capitol Lake overlooking the Washington State Capitol building in Olympia, Washington
September, the first month of the autumn, in Olympia, is still a pleasant month, with temperature in the range of an average high of 71.8°F (22.1°C) and an average low of 46°F (7.8°C).

Temperature

In Olympia, the average high-temperature slightly decreases, from a warm 77.7°F (25.4°C) in August, to a pleasant 71.8°F (22.1°C). In Olympia, in September, the average low-temperature is 46°F (7.8°C).

Humidity

In Olympia, Washington, the average relative humidity in September is 77.6%.

Rainfall

In Olympia, during September, the rain falls for 7.8 days and regularly aggregates up to 1.7" (43.4mm) of precipitation. Throughout the year, there are 162.8 rainfall days, and 50" (1270mm) of precipitation is accumulated.

Snowfall

Throughout the year, in Olympia, 10.8" (274.4mm) of snow is accumulated.

Daylight

In Olympia, Washington, the average length of the day is 12.5h.

Sunshine

In September, the average sunshine in Olympia is 7h.

UV index

In Olympia, the average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to the UV radiation for ordinary individuals.
The average daily UV index of 5 in September transform into the following instructions:
Take precautions - Protection against sunburn is recommended. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.

What is the temperature in September in Olympia?

In Olympia, in September, the average high-temperature is 71.8°F (22.1°C), and the average low-temperature is 46°F (7.8°C).

What is the average humidity in September in Olympia?

The average relative humidity in September is 77.6%.

How much does it rain in Olympia in September?

In September, in Olympia, Washington, the rain falls for 7.8 days. Throughout September, 1.7" (43.4mm) of precipitation is accumulated.

How many hours of daylight does Olympia have in September?

The average length of the day in September in Olympia is 12.5h.

How many hours of sunshine does Olympia have in September?

In Olympia, Washington, the average sunshine in September is 7h.

What is the UV index intensity in September in Olympia?

In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium hazard to health from the exposure to the Sun's UV rays.
Average temperature in September - Olympia, WA
  • Average high temperature in September: 71.8°F

The warmest month (with the highest average high temperature) is August (77.7°F).
The month with the lowest average high temperature is December (44.2°F).

  • Average low temperature in September: 46°F

The month with the highest average low temperature is July (50.8°F).
The coldest month (with the lowest average low temperature) is December (32.6°F).

Average humidity in September - Olympia, WA
  • Average humidity in September: 77.6%

The month with the highest relative humidity is December (89.1%).
The month with the lowest relative humidity is July (70.8%).

Average rainfall in September - Olympia, WA
  • Average rainfall in September: 1.7"

The wettest month (with the highest rainfall) is November (8.6").
The driest month (with the lowest rainfall) is July (0.6").

Average rainfall days in September - Olympia, WA
  • Average rainfall days in September: 7.8 days

The month with the highest number of rainy days is November (20.1 days).
The month with the lowest number of rainy days is July (4.6 days).

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

The month with the highest snowfall is February (4.7").
Months with the lowest snowfall are April, May, June, July, August, September and October (0").

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

The month with the highest number of snowfall days is February (2.2 days).
Months with the lowest number of snowfall days are May, June, July, August, September and October (0 days).

Average daylight in September / Average sunshine in September - Olympia, WA
  • Average daylight in September: 12.5h

The month with the longest days is June (Average daylight: 15.8h).
The month with shortest days is December (Average daylight: 8.6h).

  • Average sunshine in September: 7h

The month with most sunshine is July (Average sunshine: 10h).
Months with least sunshine are January and December (Average sunshine: 2).

Average UV index in September - Olympia, WA
  • Average UV index in September: 5

Months with the highest UV index are June, July and August (UV index 7).
Months with the lowest UV index are January, November and December (UV index 1).