August weather forecast
Mount Vernon, WA

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Weather in August

The weather in August in Mount Vernon continues the peak summer trend set by July. The temperatures retain their warm emissions, fluctuating between 54.1°F (12.3°C) and 68.4°F (20.2°C). Rainfall continues to remain inconsequential with averages of just 0.98" (25mm) spread over 7.2 days - the fewest rainy days in a month. The sunshine hours match the previous month. This is the last full month of summer and it provides an ideal setting for outdoor pursuits.

Temperature

July and August mark Mount Vernon's peak of temperatures, averaging a high-temperature of 68.4°F (20.2°C).

Humidity

In August, the average relative humidity is 77%.

Rainfall

In Mount Vernon, in August, during 7.2 rainfall days, 0.98" (25mm) of precipitation is typically accumulated. Throughout the year, there are 185.2 rainfall days, and 34.72" (882mm) of precipitation is accumulated.

Snowfall

May through October are months without snowfall.

Daylight

In Mount Vernon, the average length of the day in August is 14h and 16min.
On the first day of August, sunrise is at 5:45 am and sunset at 8:45 pm. On the last day of the month, sunrise is at 6:26 am and sunset at 7:52 pm PDT.

Sunshine

July and August, with an average of 10.4h of sunshine, are months with the most sunshine.

UV index

In August, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for average individuals.
Note: In August, the UV index of 4 transforms into the following advice:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Updated: Jun 20, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What part of the year is the hottest?

During July and August, Mount Vernon experiences its average highest temperatures, peaking at 68.4°F (20.2°C).

What is the usual temperature for Mount Vernon in August?

The high-temperature during August is 68.4°F (20.2°C) and the low-temperature is 54.1°F (12.3°C).

What is the average humidity in August?

In Mount Vernon, the average relative humidity in August is 77%.

How many days does it rain in August?

In Mount Vernon, during August, the rain falls for 7.2 days and regularly aggregates up to 0.98" (25mm) of precipitation.

When it does not snow?

In Mount Vernon, snow does not fall in May through October.

How many hours of daylight does Mount Vernon have in August?

In August, the average day length in Mount Vernon is 14h and 16min.

When is the sunrise / sunset in August in Mount Vernon?

On the first day of August, sunrise is at 5:45 am and sunset at 8:45 pm. On the last day of the month, sunrise is at 6:26 am and sunset at 7:52 pm PDT.

What are the months with the most sunshine?

The months with the most sunshine are July and August, with an average of 10.4h of sunshine.

How long on average sun shines in August?

In Mount Vernon, the average sunshine duration in August is 10.4h.

What is the UV index reading in August?

In August, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate health threat 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 August
Mount Vernon, WA

Average temperature in August - Mount Vernon, WA
  • Average high temperature in August: 68.4°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 August: 54.1°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 August
Mount Vernon, WA

Average pressure in August - Mount Vernon, WA
  • Average pressure in August: 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 August
Mount Vernon, WA

Average wind speed in August - Mount Vernon, WA
  • Average wind speed in August: 3.7mph

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 August
Mount Vernon, WA

Average humidity in August - Mount Vernon, WA
  • Average humidity in August: 77%

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 August
Mount Vernon, WA

Average rainfall in August - Mount Vernon, WA
  • Average rainfall in August: 0.98"

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 August
Mount Vernon, WA

Average rainfall days in August - Mount Vernon, WA
  • Average rainfall days in August: 7.2 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 August
Mount Vernon, WA

Average snowfall in August - Mount Vernon, WA
  • Average snowfall in August: 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 August
Mount Vernon, WA

Average snowfall days in August - Mount Vernon, WA
  • Average snowfall days in August: 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 August /
Average sunshine in August
Mount Vernon, WA

Average daylight in August / Average sunshine in August - Mount Vernon, WA
  • Average daylight in August: 14h and 2min

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 August: 10h and 2min

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 August
Mount Vernon, WA

Average sunshine days in August - Mount Vernon, WA
  • Average sunshine days in August: 22.3 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 August
Mount Vernon, WA

Average UV index in August - Mount Vernon, WA
  • Average UV index in August: 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 August
Mount Vernon, WA

Average cloud cover in August - Mount Vernon, WA
  • Average cloud cover in August: 26

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 August
Mount Vernon, WA

Average visibility in August - Mount Vernon, WA
  • Average visibility in August: 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).

Mount Vernon, Washington, USA

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