May weather forecast
Mount Vernon, WA

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Weather in May

During May, Mount Vernon starts to enjoy the higher temperatures with an upward movement from 7.8°C (46°F) to 15.7°C (60.3°F). This month also features longer daylight hours with an average of 15.3 hours contributing to a delightful spring ambiance. The prevalence of sunshine starts to enhance with an average of 9 hours daily. The rainfall shows a decreasing trend, diminishing to 56mm (2.2"). The wind speeds reduce further to an average of 7.4km/h (4.6mph).

Temperature

A minor escalation in the average high-temperature is seen with the onset of May, moving from a fresh 11.7°C (53.1°F) in April to a refreshing 15.7°C (60.3°F). During the month of May, the temperature generally drops to a low average of 7.8°C (46°F).

Humidity

The average relative humidity in May is 78%.

Rainfall

In May, the rain falls for 13.8 days. Throughout May, 56mm (2.2") of precipitation is accumulated. In Mount Vernon, during the entire year, the rain falls for 185.2 days and collects up to 882mm (34.72") of precipitation.

Snowfall

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

Daylight

In May, the average length of the day is 15h and 15min.
On the first day of the month, sunrise is at 5:48 am and sunset at 8:24 pm. On the last day of May, sunrise is at 5:12 am and sunset at 9:02 pm PDT.

Sunshine

In Mount Vernon, the average sunshine in May is 9h.

UV index

In Mount Vernon, the average daily maximum UV index in May is 4. A UV Index reading of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for ordinary individuals.
Note: The UV index of 4 during May leads to these advisories:
Be vigilant - Preventing sunburn is recommended. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense.
Updated: Jun 20, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in May?

During May, Mount Vernon experiences an average high-temperature of 15.7°C (60.3°F) and a low-temperature of 7.8°C (46°F).

What is the average humidity in May?

In May, the average relative humidity is 78%.

How much does it rain in May?

In Mount Vernon, in May, during 13.8 rainfall days, 56mm (2.2") of precipitation is typically accumulated.

When it does not snow?

May through October are months without snowfall.

Does it snow in May?

In May, it doesn't snow. April is the latest month when it typically snows.

What is the average length of the day in May?

In Mount Vernon, the average day length in May is 15h and 15min.

What time are sunrise and sunset in May?

On the first day of May, sunrise is at 5:48 am and sunset at 8:24 pm. On the last day of the month, sunrise is at 5:12 am and sunset at 9:02 pm PDT.

How long on average sun shines in May?

In May, the average sunshine duration is 9h.

How high is the UV index in May?

The average daily maximum UV index in May is 4. A UV Index value of 3 to 5 symbolizes a moderate health threat from unsafe 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 May
Mount Vernon, WA

Average temperature in May - Mount Vernon, WA
  • Average high temperature in May: 15.7°C

The warmest months (with the highest average high temperature) are July and August (20.2°C).
The month with the lowest average high temperature is December (5.9°C).

  • Average low temperature in May: 7.8°C

The month with the highest average low temperature is August (12.3°C).
The coldest month (with the lowest average low temperature) is February (2.3°C).

Average pressure in May
Mount Vernon, WA

Average pressure in May - Mount Vernon, WA
  • Average pressure in May: 1016.5mbar

The month with the highest atmospheric pressure is January (1018.8mbar).
The month with the lowest atmospheric pressure is March (1016.1mbar).

Average wind speed in May
Mount Vernon, WA

Average wind speed in May - Mount Vernon, WA
  • Average wind speed in May: 7.4km/h

The windiest month (with the highest average wind speed) is November (12.1km/h).
The calmest month (with the lowest average wind speed) is August (5.9km/h).

Average humidity in May
Mount Vernon, WA

Average humidity in May - Mount Vernon, WA
  • Average humidity in May: 78%

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 May
Mount Vernon, WA

Average rainfall in May - Mount Vernon, WA
  • Average rainfall in May: 56mm

The wettest month (with the highest rainfall) is November (126mm).
The driest month (with the least rainfall) is July (16mm).

Average rainfall days in May
Mount Vernon, WA

Average rainfall days in May - Mount Vernon, WA
  • Average rainfall days in May: 13.8 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 May
Mount Vernon, WA

Average snowfall in May - Mount Vernon, WA
  • Average snowfall in May: 0mm

The month with the highest snowfall is February (90mm).
The months with the least snowfall are May, June, July, August, September and October (0mm).

Average snowfall days in May
Mount Vernon, WA

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

Average daylight in May / Average sunshine in May - Mount Vernon, WA
  • Average daylight in May: 15h 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 May: 9h and 0min

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 May
Mount Vernon, WA

Average sunshine days in May - Mount Vernon, WA
  • Average sunshine days in May: 15.1 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 May
Mount Vernon, WA

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

Average cloud cover in May - Mount Vernon, WA
  • Average cloud cover in May: 42

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 May
Mount Vernon, WA

Average visibility in May - Mount Vernon, WA
  • Average visibility in May: 9km

The month with the highest visibility is July (10km).
The months with the lowest visibility are January, February, March, April, May, June, August, September, October, November and December (9km).

Mount Vernon, Washington, USA

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