September weather forecast
Cathan, WA

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Weather in September

The first month of the autumn, September, is still a refreshing month in Cathan, Washington, with temperature in the range of an average high of 66.2°F (19°C) and an average low of 49.1°F (9.5°C).

Temperature

September's onset introduces a mild reduction in the average high-temperature, from a pleasant 72.3°F (22.4°C) in August to a refreshing 66.2°F (19°C). September brings Cathan a consistent average low-temperature of 49.1°F (9.5°C).

Humidity

In Cathan, the average relative humidity in September is 78%.

Rainfall

In September, the rain falls for 13.5 days. Throughout September, 2.05" (52mm) of precipitation is accumulated. In Cathan, during the entire year, the rain falls for 188.6 days and collects up to 34.92" (887mm) of precipitation.

Snowfall

May through October are months without snowfall.

Daylight

In Cathan, the average length of the day in September is 12h and 33min.
On the first day of September in Cathan, sunrise is at 6:28 am and sunset at 7:49 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 6:49 pm PDT.

Sunshine

The average sunshine in September is 9.2h.

UV index

In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for average individuals.
Note: The maximum daily UV index of 4 during September translates into the following directions:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. To protect against the Sun's most potent rays, avoid direct exposure around midday. Enhance your sun protection with tightly woven, yet airy clothing.
Updated: Jul 22, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Cathan in September?

The average high-temperature and low-temperature during September are 66.2°F (19°C) and 49.1°F (9.5°C) respectively.

What is the average humidity in September?

In September, the average relative humidity is 78%.

How many days does it rain in September?

In Cathan, during September, the rain falls for 13.5 days and regularly aggregates up to 2.05" (52mm) of precipitation.

When it does not snow?

In Cathan, snow does not fall in May through October.

What is the average length of the day in September?

The average day length in September is 12h and 33min.

When are sunrise and sunset in September?

On the first day of September, sunrise is at 6:28 am and sunset at 7:49 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 6:49 pm PDT.

How many hours of sunshine does Cathan have in September?

In Cathan, Washington, the average sunshine duration in September is 9.2h.

How high is the UV index in September?

In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from unprotected exposure to UV radiation.
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
Cathan, WA

Average temperature in September - Cathan, WA
  • Average high temperature in September: 66.2°F

The warmest month (with the highest average high temperature) is August (72.3°F).
The month with the lowest average high temperature is December (41.7°F).

  • Average low temperature in September: 49.1°F

The month with the highest average low temperature is August (51.6°F).
The coldest month (with the lowest average low temperature) is February (33.8°F).

Average pressure in September
Cathan, WA

Average pressure in September - Cathan, WA
  • Average pressure in September: 30.01"Hg

The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).

Average wind speed in September
Cathan, WA

Average wind speed in September - Cathan, WA
  • Average wind speed in September: 3.9mph

The windiest months (with the highest average wind speed) are January and November (5.6mph).
The calmest month (with the lowest average wind speed) is August (3.3mph).

Average humidity in September
Cathan, WA

Average humidity in September - Cathan, WA
  • Average humidity in September: 78%

The months with the highest relative humidity are January, February, November and December (85%).
The month with the lowest relative humidity is July (73%).

Average rainfall in September
Cathan, WA

Average rainfall in September - Cathan, WA
  • Average rainfall in September: 2.05"

The wettest month (with the highest rainfall) is November (4.92").
The driest month (with the least rainfall) is July (0.51").

Average rainfall days in September
Cathan, WA

Average rainfall days in September - Cathan, WA
  • Average rainfall days in September: 13.5 days

The month with the highest number of rainy days is March (20.9 days).
The month with the least rainy days is August (6.9 days).

Average snowfall in September
Cathan, WA

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

The month with the highest snowfall is February (4.45").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Cathan, WA

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

The month with the highest number of snowfall days is February (4.3 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
Cathan, WA

Average daylight in September / Average sunshine in September - Cathan, WA
  • Average daylight in September: 12h and 4min

The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 24min).

  • Average sunshine in September: 9h and 1min

The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 6min).

Average sunshine days in September
Cathan, WA

Average sunshine days in September - Cathan, WA
  • Average sunshine days in September: 15.2 days

The month with the most sunshine days is August (22 days).
The month with the least sunshine days is March (8.1 days).

Average UV index in September
Cathan, WA

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

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

Average cloud cover in September
Cathan, WA

Average cloud cover in September - Cathan, WA
  • Average cloud cover in September: 34

The month with the most cloud cover is December (Cloud cover 57).
The months with the least cloud cover are July and August (Cloud cover 26).

Average visibility in September
Cathan, WA

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

The months with the highest visibility are March, April, May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February, November and December (5mi).

Cathan, Washington, USA

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