September weather forecastLynnwood, WA
September
Weather in September
September in Lynnwood signifies the transition from summer to fall with temperatures easing and rainfall beginning to pick up again. Despite the increment in rainfall, the weather remains quite warm and enjoyable. The fluctuations in weather leads to a notable increment in rainfall, reaching 1.42" (36mm). Moderation from the intense summer heat marks the arrival of the autumn season.Temperature
As September arrives, Lynnwood's weather displays a minor decrease in high-temperatures, transitioning from August's moderately hot 73.9°F (23.3°C) to a refreshing 67.6°F (19.8°C). Lynnwood encounters a steady low-temperature average of 51.6°F (10.9°C) throughout the month of September.Humidity
In September, the average relative humidity is 76%.Rainfall
In Lynnwood, in September, it is raining for 11.9 days, with typically 1.42" (36mm) of accumulated precipitation. Throughout the year, there are 173 rainfall days, and 25" (635mm) of precipitation is accumulated.Snowfall
In Lynnwood, Washington, snow does not fall in May through October.Daylight
In September, the average length of the day is 12h and 33min.On the first day of September in Lynnwood, 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
In September, the average sunshine is 9.5h.UV index
The average daily maximum UV index in September in Lynnwood is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the average person.Note: In September, an average UV index of 4 transforms into the following instructions:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Lynnwood, WA
- Average high temperature in September: 67.6°F
The warmest month (with the highest average high temperature) is August (73.9°F).
The month with the lowest average high temperature is December (43.3°F).
- Average low temperature in September: 51.6°F
The month with the highest average low temperature is August (54.1°F).
The coldest month (with the lowest average low temperature) is December (35.8°F).
Average pressure in September
Lynnwood, 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
Lynnwood, WA
- Average wind speed in September: 4mph
The windiest month (with the highest average wind speed) is November (5.9mph).
The calmest month (with the lowest average wind speed) is August (3.5mph).
Average humidity in September
Lynnwood, WA
- Average humidity in September: 76%
The months with the highest relative humidity are January, February and December (84%).
The month with the lowest relative humidity is July (72%).
Average rainfall in September
Lynnwood, WA
- Average rainfall in September: 1.42"
The wettest month (with the highest rainfall) is December (3.5").
The driest month (with the least rainfall) is July (0.39").
Average rainfall days in September
Lynnwood, WA
- Average rainfall days in September: 11.9 days
The month with the highest number of rainy days is March (19.8 days).
The month with the least rainy days is August (6.8 days).
Average snowfall in September
Lynnwood, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.58").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Lynnwood, 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
Lynnwood, WA
- Average daylight in September: 12h and 30min
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 30min).
- Average sunshine in September: 9h and 30min
The month with the most sunshine is August (Average sunshine: 10h and 48min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in September
Lynnwood, WA
- Average sunshine days in September: 15.9 days
The month with the most sunshine days is August (22.5 days).
The month with the least sunshine days is November (9.2 days).
Average UV index in September
Lynnwood, WA
- Average UV index in September: 4
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
Lynnwood, WA
- Average cloud cover in September: 32
The months with the most cloud cover are January and December (Cloud cover 53).
The month with the least cloud cover is August (Cloud cover 25).
Average visibility in September
Lynnwood, WA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
