May weather forecastRoy, WA

May

Weather in May

The last month of the spring, May, is a comfortable month in Roy, Washington, with an average temperature ranging between min 43.2°F (6.2°C) and max 65.8°F (18.8°C).

Temperature

May brings a slight increase in the average high-temperature, progressing from 57°F (13.9°C) in April to a still refreshing 65.8°F (18.8°C). Roy experiences a significant contrast between daily highs and an average nighttime temperature of 43.2°F (6.2°C) during May.

Humidity

In May, the average relative humidity is 75%.

Rainfall

In Roy, in May, it is raining for 13.4 days, with typically 1.69" (43mm) of accumulated precipitation. Throughout the year, in Roy, there are 174.2 rainfall days, and 31.06" (789mm) of precipitation is accumulated.

Snowfall

In Roy, snow does not fall in May through October.

Daylight

In May, the average length of the day in Roy is 15h and 5min.
On the first day of May in Roy, sunrise is at 5:52 am and sunset at 8:21 pm. On the last day of the month, sunrise is at 5:18 am and sunset at 8:57 pm PDT.

Sunshine

The average sunshine in May in Roy, Washington, is 8.7h.

UV index

The average daily maximum UV index in May is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.
Note: A typical high UV index of 4 in May suggests the following recommendations:
Be vigilant - A duty to shield skin and eyes from injury exists. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.

Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Roy in May has an average high-temperature of 65.8°F (18.8°C) and an average low-temperature of 43.2°F (6.2°C).

In Roy, Washington, the average relative humidity in May is 75%.

In May, in Roy, the rain falls for 13.4 days. Throughout May, 1.69" (43mm) of precipitation is accumulated.

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

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

In Roy, Washington, the average day length in May is 15h and 5min.

On the first day of May in Roy, sunrise is at 5:52 am and sunset at 8:21 pm. On the last day of the month, sunrise is at 5:18 am and sunset at 8:57 pm PDT.

In May, the average sunshine duration is 8.7h.

In May, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium hazard to health from exposure to the Sun's UV radiation.

Today

Tomorrow

Long-term

Year J F M A May J J A S O N D

Apr

May

Jun

Average high temperature

57°F

65.8°F

70.2°F

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

5.2mph

4.7mph

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average snowfall

Average snowfall days

Average daylight

Average sunshine

Average sunshine days

10.9

Average UV index

Average cloud cover

Average visibility

Average temperature in May
Roy, WA

Average high temperature in May: 65.8°F

The warmest month (with the highest average high temperature) is August (78.4°F).
The month with the lowest average high temperature is December (43.5°F).

Average low temperature in May: 43.2°F

The month with the highest average low temperature is August (52.2°F).
The coldest month (with the lowest average low temperature) is February (34°F).

Average pressure in May
Roy, WA

Average pressure in May: 30.03"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 May
Roy, WA

Average wind speed in May: 4.2mph

The windiest month (with the highest average wind speed) is March (5mph).
The calmest month (with the lowest average wind speed) is August (3.7mph).

Average humidity in May
Roy, WA

Average humidity in May: 75%

The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is July (69%).

Average rainfall in May
Roy, WA

Average rainfall in May: 1.69"

The wettest month (with the highest rainfall) is December (4.96").
The driest month (with the least rainfall) is July (0.35").

Average rainfall days in May
Roy, WA

Average rainfall days in May: 13.4 days

The month with the highest number of rainy days is March (19.7 days).
The month with the least rainy days is August (5.2 days).

Average snowfall in May
Roy, WA

Average snowfall in May: 0"

The month with the highest snowfall is February (1.73").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in May
Roy, WA

Average snowfall days in May: 0 days

The month with the highest number of snowfall days is February (2.8 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
Roy, WA

Average daylight in May: 15h and 6min

The month with the longest days is June (Average daylight: 15h and 48min).
The month with the shortest days is December (Average daylight: 8h and 36min).

Average sunshine in May: 8h and 42min

The month with the most sunshine is August (Average sunshine: 10h and 36min).
The month with the least sunshine is December (Average sunshine: 3h and 54min).

Average sunshine days in May
Roy, WA

Average sunshine days in May: 16 days

The month with the most sunshine days is August (22.9 days).
The month with the least sunshine days is November (9.1 days).

Average UV index in May
Roy, WA

Average UV index in May: 4

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in May
Roy, WA

Average cloud cover in May: 46

The months with the most cloud cover are January and December (Cloud cover 59).
The months with the least cloud cover are July and August (Cloud cover 28).