September weather forecastCathan, WA
September
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.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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: 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: 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: 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: 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: 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: 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: 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: 12h and 36min
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 12min
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: 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: 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: 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: 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).
