September weather forecastCathlamet, WA
September
Weather in September
September, the first month of the autumn in Cathlamet, is still a pleasant month, with an average temperature ranging between max 69.6°F (20.9°C) and min 47.3°F (8.5°C).Temperature
A moderate decline in average high-temperatures is noted in September, moving from a moderately hot 76.5°F (24.7°C) in August to an agreeable 69.6°F (20.9°C). A sharp divergence from daytime highs is noted during the month of September, with the average nighttime temperature settling at a frosty 47.3°F (8.5°C).Humidity
In September, the average relative humidity is 80%.Rainfall
In Cathlamet, during September, the rain falls for 9.2 days and regularly aggregates up to 0.67" (17mm) of precipitation. In Cathlamet, during the entire year, the rain falls for 141.6 days and collects up to 11.57" (294mm) of precipitation.Snowfall
April through November are months without snowfall in Cathlamet.Daylight
In Cathlamet, the average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:35 am and sunset at 7:51 pm. On the last day of September, sunrise is at 7:11 am and sunset at 6:54 pm PDT.
Sunshine
In Cathlamet, Washington, the average sunshine in September is 8.1h.UV index
The average daily maximum UV index in September in Cathlamet is 3. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for average individuals.Note: A maximum high UV index of 3 in September translates into the following recommendations:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. Always opt for UVA and UVB-resistant sunglasses on radiant days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Cathlamet, WA
- Average high temperature in September: 69.6°F
The warmest month (with the highest average high temperature) is August (76.5°F).
The month with the lowest average high temperature is December (42.3°F).
- Average low temperature in September: 47.3°F
The month with the highest average low temperature is August (49.8°F).
The coldest month (with the lowest average low temperature) is December (32.9°F).
Average pressure in September
Cathlamet, WA
- Average pressure in September: 30.02"Hg
The months with the highest atmospheric pressure are January and December (30.09"Hg).
The months with the lowest atmospheric pressure are March, August and September (30.02"Hg).
Average wind speed in September
Cathlamet, WA
- Average wind speed in September: 3.8mph
The windiest month (with the highest average wind speed) is January (4.9mph).
The calmest month (with the lowest average wind speed) is September (3.8mph).
Average humidity in September
Cathlamet, WA
- Average humidity in September: 80%
The months with the highest relative humidity are February, November and December (89%).
The month with the lowest relative humidity is July (75%).
Average rainfall in September
Cathlamet, WA
- Average rainfall in September: 0.67"
The wettest month (with the highest rainfall) is January (1.77").
The driest month (with the least rainfall) is August (0.24").
Average rainfall days in September
Cathlamet, WA
- Average rainfall days in September: 9.2 days
The month with the highest number of rainy days is March (16.3 days).
The month with the least rainy days is August (4.7 days).
Average snowfall in September
Cathlamet, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.55").
The months with the least snowfall are April, May, June, July, August, September, October and November (0").
Average snowfall days in September
Cathlamet, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.8 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Cathlamet, WA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in September: 8h and 6min
The month with the most sunshine is August (Average sunshine: 10h and 0min).
The month with the least sunshine is February (Average sunshine: 3h and 12min).
Average sunshine days in September
Cathlamet, WA
- Average sunshine days in September: 18.5 days
The month with the most sunshine days is August (24.6 days).
The month with the least sunshine days is April (11.7 days).
Average UV index in September
Cathlamet, WA
- Average UV index in September: 3
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
Cathlamet, WA
- Average cloud cover in September: 48
The months with the most cloud cover are February and March (Cloud cover 68).
The month with the least cloud cover is August (Cloud cover 42).
Average visibility in September
Cathlamet, WA
- Average visibility in September: 4mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (4mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (4mi).
