September weather forecastLynden, WA
September
Weather in September
The first month of the autumn, September, is still a comfortable month in Lynden, Washington, with an average temperature fluctuating between 66.7°F (19.3°C) and 47.5°F (8.6°C).Temperature
A minor decrease in the average high-temperature is observed during September, shifting from a warm 73.6°F (23.1°C) in August to a refreshing 66.7°F (19.3°C). Throughout September, the average low-temperature in Lynden dips to a frosty 47.5°F (8.6°C).Humidity
In Lynden, the average relative humidity in September is 78%.Rainfall
In Lynden, Washington, in September, during 14.5 rainfall days, 2.87" (73mm) of precipitation is typically accumulated. In Lynden, during the entire year, the rain falls for 188 days and collects up to 49.88" (1267mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
The average length of the day in September is 12h and 34min.On the first day of the month, sunrise is at 6:27 am and sunset at 7:51 pm. On the last day of September, sunrise is at 7:09 am and sunset at 6:49 pm PDT.
Sunshine
In Lynden, Washington, the average sunshine in September is 8.8h.UV index
In Lynden, Washington, the average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: The average daily UV index of 3 in September transforms into the following instructions:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Lynden, WA
- Average high temperature in September: 66.7°F
The warmest month (with the highest average high temperature) is August (73.6°F).
The month with the lowest average high temperature is December (39.6°F).
- Average low temperature in September: 47.5°F
The month with the highest average low temperature is August (51.4°F).
The coldest months (with the lowest average low temperature) are February and December (31.6°F).
Average pressure in September
Lynden, 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 and August (30"Hg).
Average wind speed in September
Lynden, WA
- Average wind speed in September: 3.4mph
The windiest months (with the highest average wind speed) are January and February (4.7mph).
The calmest month (with the lowest average wind speed) is August (3.2mph).
Average humidity in September
Lynden, WA
- Average humidity in September: 78%
The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is July (73%).
Average rainfall in September
Lynden, WA
- Average rainfall in September: 2.87"
The wettest month (with the highest rainfall) is November (7.72").
The driest month (with the least rainfall) is July (0.91").
Average rainfall days in September
Lynden, WA
- Average rainfall days in September: 14.5 days
The month with the highest number of rainy days is March (20.5 days).
The month with the least rainy days is August (7.8 days).
Average snowfall in September
Lynden, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.11").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Lynden, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (4.7 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
Lynden, WA
- Average daylight in September: 12h and 36min
The month with the longest days is June (Average daylight: 16h and 6min).
The month with the shortest days is December (Average daylight: 8h and 18min).
- Average sunshine in September: 8h and 48min
The month with the most sunshine is August (Average sunshine: 10h and 18min).
The month with the least sunshine is December (Average sunshine: 3h and 48min).
Average sunshine days in September
Lynden, WA
- Average sunshine days in September: 14.2 days
The months with the most sunshine days are July and August (21 days).
The month with the least sunshine days is March (8.4 days).
Average UV index in September
Lynden, WA
- Average UV index in September: 3
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
Lynden, WA
- Average cloud cover in September: 39
The month with the most cloud cover is March (Cloud cover 60).
The months with the least cloud cover are July and August (Cloud cover 30).
Average visibility in September
Lynden, WA
- Average visibility in September: 5mi
The months with the highest visibility are April, May, June, July, August, September and October (5mi).
The months with the lowest visibility are January, February, March, November and December (4mi).
