September weather forecast
Marysville, WA

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Weather in September

September signifies the start of autumn in Marysville, bringing a hearty blend of sunshine-filled days and cool nights. September ushers in a gradual decrease in temperatures from 73°F (22.8°C) in August to a milder 67.1°F (19.5°C). The drop in temperature attributes itself to the shorter daylight hours and the slightly increased cloud cover. The humidity levels hold firm, and the wind speed begins to increase, lending a crisp feeling to the air. While rainfall starts to regain its place, outdoor adventures remain popular due to the pleasant conditions.

Temperature

The transition into September in Marysville is accompanied by a slight temperature decrease, with the average high-temperature shifting from an agreeable 73°F (22.8°C) in August to a refreshing 67.1°F (19.5°C). During the month of September, the nighttime temperature in Marysville falls to an average of 50°F (10°C).

Humidity

The average relative humidity in September in Marysville is 77%.

Rainfall

In Marysville, Washington, in September, it is raining for 12.3 days, with typically 1.77" (45mm) of accumulated precipitation. Throughout the year, there are 179.1 rainfall days, and 29.57" (751mm) of precipitation is accumulated.

Snowfall

May through October are months without snowfall.

Daylight

In Marysville, the average length of the day in September is 12h and 33min.
On the first day of the month, sunrise is at 6:27 am and sunset at 7:49 pm. On the last day of September, in Marysville, sunrise is at 7:07 am and sunset at 6:49 pm PDT.

Sunshine

In September, the average sunshine is 9.2h.

UV index

The average daily maximum UV index in September in Marysville, Washington, is 3. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.
Note: The daily maximum UV index of 3 in September interprets into the following advice:
Make use of precautions - It is urged to ward off sun damage. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. To cut down UV radiation exposure by about half, sport a wide-brim hat.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures in Marysville?

The high-temperature, in September, in Marysville, records 67.1°F (19.5°C), while the low-temperature is 50°F (10°C).

What is the average humidity in September in Marysville?

The average relative humidity in September in Marysville is 77%.

How many days does it rain in September in Marysville?

In Marysville, Washington, in September, during 12.3 rainfall days, 1.77" (45mm) of precipitation is typically accumulated.

When it does not snow in Marysville?

In Marysville, Washington, snow does not fall in May through October.

How many hours of daylight does Marysville have in September?

In Marysville, the average day length in September is 12h and 33min.

What time are sunrise and sunset in September in Marysville?

On the first day of September, sunrise is at 6:27 am and sunset at 7:49 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:49 pm PDT.

How long on average sun shines in September in Marysville?

In September, the average sunshine duration in Marysville is 9.2h.

How high is the UV index in September in Marysville?

The average daily maximum UV index in September in Marysville, Washington, is 3. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Marysville, WA

Average temperature in September - Marysville, WA
  • Average high temperature in September: 67.1°F

The warmest month (with the highest average high temperature) is August (73°F).
The month with the lowest average high temperature is December (42.3°F).

  • Average low temperature in September: 50°F

The month with the highest average low temperature is August (52.5°F).
The coldest month (with the lowest average low temperature) is December (34.7°F).

Average pressure in September
Marysville, WA

Average pressure in September - Marysville, 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
Marysville, WA

Average wind speed in September - Marysville, WA
  • Average wind speed in September: 4mph

The windiest months (with the highest average wind speed) are March and November (5.8mph).
The calmest month (with the lowest average wind speed) is August (3.5mph).

Average humidity in September
Marysville, WA

Average humidity in September - Marysville, WA
  • Average humidity in September: 77%

The months with the highest relative humidity are January and December (85%).
The month with the lowest relative humidity is July (73%).

Average rainfall in September
Marysville, WA

Average rainfall in September - Marysville, WA
  • Average rainfall in September: 1.77"

The wettest month (with the highest rainfall) is November (4.06").
The driest month (with the least rainfall) is July (0.47").

Average rainfall days in September
Marysville, WA

Average rainfall days in September - Marysville, WA
  • Average rainfall days in September: 12.3 days

The month with the highest number of rainy days is March (19.8 days).
The month with the least rainy days is August (6.1 days).

Average snowfall in September
Marysville, WA

Average snowfall in September - Marysville, WA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (2.68").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Marysville, WA

Average snowfall days in September - Marysville, WA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (3.1 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
Marysville, WA

Average daylight in September / Average sunshine in September - Marysville, WA
  • Average daylight in September: 12h and 4min

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 1min

The month with the most sunshine is August (Average sunshine: 10h and 36min).
The months with the least sunshine are January and December (Average sunshine: 4h and 12min).

Average sunshine days in September
Marysville, WA

Average sunshine days in September - Marysville, WA
  • Average sunshine days in September: 16.1 days

The month with the most sunshine days is August (23.1 days).
The months with the least sunshine days are February and November (8.6 days).

Average UV index in September
Marysville, WA

Average UV index in September - Marysville, 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
Marysville, WA

Average cloud cover in September - Marysville, WA
  • Average cloud cover in September: 34

The month with the most cloud cover is December (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 26).

Average visibility in September
Marysville, WA

Average visibility in September - Marysville, 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).

Marysville, Washington, USA

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