Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
In Mount Vernon, the average high-temperature in September is almost the same as in August - a comfortable 64°F (17.8°C). In Mount Vernon, Washington, the average low-temperature is 51.4°F (10.8°C).Humidity
The average relative humidity in September is 79%.Rainfall
In Mount Vernon, during September, the rain falls for 12.1 days and regularly aggregates up to 2.24" (57mm) of precipitation. Throughout the year, there are 185.2 rainfall days, and 34.72" (882mm) of precipitation is accumulated.Snowfall
In Mount Vernon, snow does not fall in May through October.Daylight
In September, the average length of the day is 12h and 34min.On the first day of the month, sunrise is at 6:26 am and sunset at 7:51 pm. On the last day of September, in Mount Vernon, Washington, sunrise is at 7:07 am and sunset at 6:51 pm PDT.
Sunshine
In September, the average sunshine is 9h.UV index
In September, the average daily maximum UV index in Mount Vernon is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for average individuals.Note: The average daily UV index of 4 in September transform into the following instructions:
Take precautions - Protection against skin and eye damage is obliged. 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 the 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.
FAQ
What is the temperature in September in Mount Vernon?
What is the average humidity in September in Mount Vernon?
How much does it rain in Mount Vernon in September?
When it does not snow in Mount Vernon?
What is the average length of the day in September in Mount Vernon?
When are sunrise and sunset in September in Mount Vernon?
How long on average sun shines in September in Mount Vernon?
How high is the UV index in September in Mount Vernon?
Average temperature in September
Mount Vernon, WA
- Average high temperature in September: 64°F
The warmest months (with the highest average high temperature) are July and August (68.4°F).
The month with the lowest average high temperature is December (42.6°F).
- Average low temperature in September: 51.4°F
The month with the highest average low temperature is August (54.1°F).
The coldest month (with the lowest average low temperature) is February (36.1°F).
Average pressure in September
Mount Vernon, WA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The months with the lowest atmospheric pressure are March, August and September (30.01"Hg).
Average wind speed in September
Mount Vernon, WA
- Average wind speed in September: 4.5mph
The windiest month (with the highest average wind speed) is November (7.5mph).
The calmest month (with the lowest average wind speed) is August (3.7mph).
Average humidity in September
Mount Vernon, WA
- Average humidity in September: 79%
The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is July (75%).
Average rainfall in September
Mount Vernon, WA
- Average rainfall in September: 2.24"
The wettest month (with the highest rainfall) is November (4.96").
The driest month (with the least rainfall) is July (0.63").
Average rainfall days in September
Mount Vernon, WA
- Average rainfall days in September: 12.1 days
The month with the highest number of rainy days is March (20.8 days).
The month with the least rainy days is August (7.2 days).
Average snowfall in September
Mount Vernon, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.54").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Mount Vernon, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3.6 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
Mount Vernon, WA
- Average daylight in September: 12h and 34min
The month with the longest days is June (Average daylight: 16h and 2min).
The month with the shortest days is December (Average daylight: 8h and 23min).
- Average sunshine in September: 9h and 0min
The months with the most sunshine are July and August (Average sunshine: 10h and 24min).
The month with the least sunshine is December (Average sunshine: 3h and 54min).
Average sunshine days in September
Mount Vernon, WA
- Average sunshine days in September: 16.3 days
The month with the most sunshine days is August (22.3 days).
The month with the least sunshine days is November (8.1 days).
Average UV index in September
Mount Vernon, 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, November and December (UV index 2).
Average cloud cover in September
Mount Vernon, WA
- Average cloud cover in September: 34
The month with the most cloud cover is December (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 26).
Average visibility in September
Mount Vernon, WA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
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