September weather forecast
Kittitas, WA

Share

Weather in September

The first month of the autumn, September, is also an agreeable month in Kittitas, Washington, with an average temperature fluctuating between 49.1°F (9.5°C) and 71.1°F (21.7°C).

Temperature

During the transition into September, Kittitas observes a decrease in the average high-temperature, falling from a moderately hot 82°F (27.8°C) in August to a pleasant 71.1°F (21.7°C). September nights report a substantial dip from daytime highs to an average of 49.1°F (9.5°C).

Humidity

The average relative humidity in September in Kittitas is 54%.

Rainfall

In September, in Kittitas, Washington, the rain falls for 6.1 days. Throughout September, 0.47" (12mm) of precipitation is accumulated. In Kittitas, during the entire year, the rain falls for 99.9 days and collects up to 8.66" (220mm) of precipitation.

Snowfall

January through April, September through December are months with snowfall in Kittitas. September is the first month it typically snows in Kittitas, Washington. Throughout September, in the average 0.3 snowfall days, it receives 0.31" (8mm) of snow. Throughout the year, there are 35.4 snowfall days, and 15.59" (396mm) of snow is accumulated.

Daylight

In September, the average length of the day is 12h and 32min.
On the first day of the month, sunrise is at 6:22 am and sunset at 7:40 pm. On the last day of September, in Kittitas, sunrise is at 7:00 am and sunset at 6:42 pm PDT.

Sunshine

The average sunshine in September is 10.7h.

UV index

In Kittitas, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the average person.
Note: A maximum high daily UV index of 4 during September translates into the following directions:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Note this! The Sun's UV radiation can nearly be doubled by the reflection off snow.
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 Kittitas in September?

September temperatures in Kittitas vary between a high-temperature of 71.1°F (21.7°C) and a low-temperature of 49.1°F (9.5°C). In August, the average heat index (a.k.a. 'real feel', 'feels like'), which takes the relative humidity and factors it into the air temperature reading, is estimated at 82.4°F (28°C).

What is the average humidity in September in Kittitas?

The average relative humidity in September in Kittitas, Washington, is 54%.

How much does it rain in Kittitas in September?

In Kittitas, during September, the rain falls for 6.1 days and regularly aggregates up to 0.47" (12mm) of precipitation.

When does it start snowing in Kittitas?

September is the first month it typically snows in Kittitas, Washington. Throughout September, in the average 0.3 snowfall days, it receives 0.31" (8mm) of snow.

How many hours of daylight does Kittitas have in September?

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

When is the sunrise / sunset in September in Kittitas?

On the first day of September, sunrise is at 6:22 am and sunset at 7:40 pm. On the last day of the month, sunrise is at 7:00 am and sunset at 6:42 pm PDT.

How long on average sun shines in September in Kittitas?

The average sunshine duration in September in Kittitas, Washington, is 10.7h.

How high is the UV index in September in Kittitas?

In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium health risk from 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
Kittitas, WA

Average temperature in September - Kittitas, WA
  • Average high temperature in September: 71.1°F

The warmest months (with the highest average high temperature) are July and August (82°F).
The month with the lowest average high temperature is December (33.3°F).

  • Average low temperature in September: 49.1°F

The month with the highest average low temperature is August (55.2°F).
The coldest month (with the lowest average low temperature) is December (21.4°F).

Average pressure in September
Kittitas, WA

Average pressure in September - Kittitas, WA
  • Average pressure in September: 29.97"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is August (29.94"Hg).

Average wind speed in September
Kittitas, WA

Average wind speed in September - Kittitas, WA
  • Average wind speed in September: 6.9mph

The windiest month (with the highest average wind speed) is June (8.9mph).
The calmest month (with the lowest average wind speed) is December (4.2mph).

Average humidity in September
Kittitas, WA

Average humidity in September - Kittitas, WA
  • Average humidity in September: 54%

The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are July and August (46%).

Average rainfall in September
Kittitas, WA

Average rainfall in September - Kittitas, WA
  • Average rainfall in September: 0.47"

The wettest month (with the highest rainfall) is December (1.3").
The driest month (with the least rainfall) is July (0.16").

Average rainfall days in September
Kittitas, WA

Average rainfall days in September - Kittitas, WA
  • Average rainfall days in September: 6.1 days

The month with the highest number of rainy days is March (12.4 days).
The month with the least rainy days is August (2.8 days).

Average snowfall in September
Kittitas, WA

Average snowfall in September - Kittitas, WA
  • Average snowfall in September: 0.31"

The month with the highest snowfall is December (4.65").
The months with the least snowfall are May, June, July and August (0").

Average snowfall days in September
Kittitas, WA

Average snowfall days in September - Kittitas, WA
  • Average snowfall days in September: 0.3 days

The months with the highest number of snowfall days are January and December (8.7 days).
The months with the least snowfall days are May, June, July and August (0 days).

Average daylight in September /
Average sunshine in September
Kittitas, WA

Average daylight in September / Average sunshine in September - Kittitas, 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: 10h and 4min

The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The months with the least sunshine are January and December (Average sunshine: 4h and 48min).

Average sunshine days in September
Kittitas, WA

Average sunshine days in September - Kittitas, WA
  • Average sunshine days in September: 22.8 days

The month with the most sunshine days is July (27.1 days).
The month with the least sunshine days is February (13.5 days).

Average UV index in September
Kittitas, WA

Average UV index in September - Kittitas, WA
  • Average UV index in September: 4

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).

Average cloud cover in September
Kittitas, WA

Average cloud cover in September - Kittitas, WA
  • Average cloud cover in September: 18

The month with the most cloud cover is January (Cloud cover 48).
The months with the least cloud cover are July and August (Cloud cover 11).

Average visibility in September
Kittitas, WA

Average visibility in September - Kittitas, WA
  • Average visibility in September: 6mi

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

Kittitas, Washington, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location