Climate and monthly weather forecast
Mount Vernon, WA

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Climate and monthly weather forecast

The climate of Mount Vernon

Mount Vernon, a city located in Washington, USA, experiences a Mediterranean warm summer climate, often referred to as a "Csb" according to the Köppen climate classification. The city's geographical position accentuates the moderate temperature range and endows it with a fair amount of rainfall per annum.

Throughout the year, Mount Vernon's weather distinctly oscillates, with temperatures ranging from a low of 36°F (2.2°C) in February to a high of 68.4°F (20.2°C) from July to August. The humidity remains consistently high, hovering around 82% during the colder months of December and January and falling to a relative low of 75% in July. Mount Vernon experiences rainfall for more than half the year, with November witnessing the highest volume of rain, approximately 4.96" (126mm), and July receiving the least, around 0.63 inch.

While the city doesn’t see much of a change in cloud percentage and visibility throughout the year, wind speeds generally pick up from October, reaching a peak of 7.5mph (12.1km/h) in November. Sunshine hours dramatically increase from January's 4 to July's 10.4, paralleling the rise in UV index from 2 to 5. The months of February and March witness a peak in snowfall, with 3.54" (90mm) and 1.38" (35mm) respectively.

Unique weather patterns revolve around its position close to the coastline, thus ensuring relatively tempered highs and lows in terms of temperature while maintaining a wet climate overall. For snow lovers, the sight of the city receiving sparse snow, mainly in the early months of the year, emerges as a unique spectacle.

The best time to visit Mount Vernon

The suitable time for scheduling a trip to Mount Vernon lies from June to August. The pleasant weather conditions during this time of the year, with temperatures spiralling to 68.4°F (20.2°C), make it ideal for outdoor activities. The daylight hours peak around June, reaching up to 16 hours, allowing tourists to make the most of their visit. Correspondingly, the city is less wet during these months, with the least rainfall recorded in July at 0.63" (16mm), complementing sightseeing and unhampered by sudden bouts of rain.

The worst time to visit Mount Vernon

For tourists not particularly fond of rain, the period from October through December might seem less than ideal for a visit. November receives the highest amount of rainfall, around 4.96" (126mm), which could dampen outdoor plans. Coupled with the reduced sunshine hours, reduced to 4.3 hours a day in November, the weather can be quite gloomy and cold.

Spring weather in Mount Vernon

The commencement of Spring in Mount Vernon ushers in a gradual rise in temperature from 48.2°F (9°C) in March to 60.3°F (15.7°C) in May. Concurrently, the volume of rainfall decreases substantially from 3.74" (95mm) in March to 2.2" (56mm) in May, hinting at the transition towards the drier summer months. Wind speed experiences a noticeable dip during this period, dropping from 6.8mph (10.9km/h) in March to 4.6mph (7.4km/h) in May. While the snowfall ceases, daylight hours start to increase, reaching up to 15.3 hours by the end of spring.

Summer weather in Mount Vernon

Summer in Mount Vernon peaks from June to August, with the highest temperature consistently maintained at 68.4°F (20.2°C). It showcases a significant drop in rainfall, resulting in a dry atmosphere with a relative bottom-out humidity of 75%. The sunshine hours also reach their zenith in these months, with almost 10.4 hours of sunshine per day, resulting in a UV index increase.

Autumn weather in Mount Vernon

The arrival of autumn from September to November brings about a decrease in the average temperature, going from 64°F (17.8°C) in September down to 47.8°F (8.8°C) in November. Corresponding to the drop in temperature, the rainfall sees a stark increase, especially pronounced in November which receives the maximum rainfall of 4.96" (126mm) in the entire year. The wind speed picks pace with an average speed of 7.5mph (12.1km/h) becoming standard in November, the highest of the entire year.

Winter weather in Mount Vernon

Winter in Mount Vernon unfolds a cooler climate with temperatures resting between 42.6°F (5.9°C) to 44.2°F (6.8°C) from December to February. Although snowfall is infrequent, it does grace the city sometimes, reaching 3.54" (90mm) in February. Despite the short daylight hours hovering around 8.4- 8.9 hours, the city shines resplendent with holiday decorations, adding to the winter charm. Nevertheless, with higher rainfall, thicker cloud cover, and lower temperatures, it may not be the ideal time to visit unless winter activities are on the itinerary.

Weather in January

Mount Vernon in January experiences considerable cloudiness with a relative humidity of 83% and an average of 18.3 rainfall days. Unpredictable weather patterns contribute to an average segment of just 9 hours of sunshine each day. Weather in January »

Weather in February

The weather patterns for February in Mount Vernon tend to show some similarities to those of January. The month usually witnesses a slightly reduced average rainfall of 3.62" (92mm). A slight increase in average low temperature to 36.1°F (2.3°C) is also noteworthy. Weather in February »

Weather in March

March brings a noticeable shift in weather conditions in Mount Vernon. The average low temperature starts to rise arriving at 38.8°F (3.8°C), while the high temperature pushes its way up to 48.2°F (9°C). With an average of 3.74" (95mm) of rainfall, this month can be expected to have a fair number of wet days. Weather in March »

Weather in April

The weather in Mount Vernon in April further opens the door to spring. The increasing warmth is seen in the rising temperatures, spanning from 41.9 degrees on cooler days to a pleasant 53.1 degrees on warmer ones. Although the rainfall reduces to 2.91" (74mm), it is still distributed over a substantial 19.2 days. Weather in April »

Weather in May

During May, Mount Vernon starts to enjoy the higher temperatures with an upward movement from 46°F (7.8°C) to 60.3°F (15.7°C). This month also features longer daylight hours with an average of 15.3 hours contributing to a delightful spring ambiance. Weather in May »

Weather in June

June sets the stage for summer in Mount Vernon, with the warmer scale of temperature ranging from 49.3°F (9.6°C) to 63.9°F (17.7°C). This increment in temperature is accompanied by a diminishing intensity of rainfall. With just 1.54" (39mm) of rainfall over 12.4 days, June is relatively dry compared to the preceding months. Weather in June »

Weather in July

July is a month of warmth and optimal sunlight in Mount Vernon. This month sees the maximum temperature magnitude of 68.4°F (20.2°C) which is a significant shift from the past months. The prevalence of sunshine becomes more evident - the day enjoys a beautiful stretch of 10.4 hours of sunshine, on average. Weather in July »

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. Weather in August »

Weather in September

September signals the transition towards autumn in Mount Vernon, yet the summer warmth still lingers. The temperatures now range from a pleasant 51.4°F (10.8°C) to a still warm 64°F (17.8°C). There is an increase in rainfall levels to 2.24" (57mm), indicating the impending change of the season. Weather in September »

Weather in October

The weather in October in Mount Vernon showcases the essence of fall with pronounced changes in the atmosphere. Temperatures continue their descent, ranging from 46.2°F (7.9°C) to 55.8°. The rainfall increases significantly to 3.7" (94mm) - the city starts to witness more rainy days underscoring the arrival of the colder seasons. Weather in October »

Weather in November

November in Mount Vernon is a prelude to winter. The air is colder with temperatures ranging between 41.2°F (5.1°C) and 47.8°F (8.8°C). Rainfall is at its maximum in November, reaching 4.96" (126mm) over 20.7 days. The daylight hours are quite short, restricting the amount of sunshine. Weather in November »

Weather in December

December announces the onset of winter in Mount Vernon. The average temperatures hit their yearly lows, commencing at 36.3°F (2.4°C) and managing to reach only up to 42.6°F (5.9°C). Despite being the cold month, December receives 4.06" (103mm) of rainfall but also sees a slight increase in snowfall to 0.47" (12mm) over 1.5 days. Weather in December »
Updated: Jun 20, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the most humid months?
The months with the highest humidity are January and February, with an average relative humidity of 83%.
How many days does it rain?
In Mount Vernon, during the entire year, the rain falls for 185.2 days and collects up to 34.72" (882mm) of precipitation.
When does it snow?
Months with snowfall are January through April, November and December.
How much does it snow?
Throughout the year, there are 9.9 snowfall days, and 7.91" (201mm) of snow is accumulated.
What is the month with the lowest UV index?
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index.
When does it snow the most?
The month with the most snowfall is February, when snow falls for 3.6 days and typically aggregates up to 3.54" (90mm) of snow.
When is Daylight Saving Time (DST)?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from PST to PDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from PDT to PST.
When it does not snow in Mount Vernon?
May through October are months without snowfall.
When are the longest days in Mount Vernon?
June has the longest days of the year, with an average of 16h and 0min of daylight.
What is the warmest month?
Mount Vernon experiences its warmest period in July and August, averaging a high-temperature of 68.4°F (20.2°C).
What is the least humid month in Mount Vernon?
The least humid month is July, with an average relative humidity of 75%.
What is the driest month?
The month with the least rainfall is July, when the rain falls for 7.9 days and typically collects 0.63" (16mm) of precipitation.
What are the months with the most sunshine?
July and August, with an average of 10.4h of sunshine, are months with the most sunshine.
What is the month with the highest UV index?
With an average maximum UV index of 5, July is the month with the highest UV index.
What is the wettest month?
The month with the most rainfall is November, when the rain falls for 20.7 days and typically aggregates up to 4.96" (126mm) of precipitation.
What part of the year is the coldest?
The coldest period tends to be December, when average temperatures fluctuate between a high of 42.6°F (5.9°C) and a low of 36.3°F (2.4°C).
What is the month with the shortest days?
With an average of 8h and 24min of daylight, December has the shortest days of the year in Mount Vernon.
What is the month with the least sunshine?
December has the least sunshine of the year, with an average of 3.9h of sunshine.
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Average temperature - Mount Vernon, WA
Average temperature
Mount Vernon, WA

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).

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 - Mount Vernon, WA
Average pressure
Mount Vernon, WA

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 - Mount Vernon, WA
Average wind speed
Mount Vernon, WA

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 - Mount Vernon, WA
Average humidity
Mount Vernon, WA

The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is July (75%).

Average rainfall - Mount Vernon, WA
Average rainfall
Mount Vernon, WA

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 - Mount Vernon, WA
Average rainfall days
Mount Vernon, WA

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 - Mount Vernon, WA
Average snowfall
Mount Vernon, WA

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 - Mount Vernon, WA
Average snowfall days
Mount Vernon, WA

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 / Average sunshine - Mount Vernon, WA
Average daylight / Average sunshine
Mount Vernon, WA

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).

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 - Mount Vernon, WA
Average sunshine days
Mount Vernon, WA

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 - Mount Vernon, WA
Average UV index
Mount Vernon, WA

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 - Mount Vernon, WA
Average cloud cover
Mount Vernon, WA

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 - Mount Vernon, WA
Average visibility
Mount Vernon, WA

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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