May weather forecast
Rock Island, WA

Share

Weather in May

The last month of the spring, May, is an enjoyable month in Rock Island, Washington, with an average temperature fluctuating between 66°F (18.9°C) and 43.3°F (6.3°C).

Temperature

In Rock Island, stepping into May brings a temperature increase, moving up from April's moderate 55.4°F (13°C) to a still refreshing 66°F (18.9°C). Rock Island demonstrates a significant disparity from daytime highs throughout the month of May, with an average nighttime temperature of 43.3°F (6.3°C).

Humidity

In Rock Island, the average relative humidity in May is 57%.

Rainfall

In Rock Island, in May, it is raining for 10.8 days, with typically 1.18" (30mm) of accumulated precipitation. In Rock Island, during the entire year, the rain falls for 111.7 days and collects up to 10.71" (272mm) of precipitation.

Snowfall

May through August and October are months without snowfall in Rock Island.

Daylight

In Rock Island, the average length of the day in May is 15h and 8min.
On the first day of May in Rock Island, sunrise is at 5:42 am and sunset at 8:12 pm. On the last day of the month, sunrise is at 5:07 am and sunset at 8:49 pm PDT.

Sunshine

In May, the average sunshine in Rock Island, Washington, is 11h.

UV index

The average daily maximum UV index in May is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In May, the maximum UV index of 5 transforms into these recommendations:
Make use of precautions - Shielding skin and eyes from injury is a requirement. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Stay sun-safe with clothing that is both closely woven and worn loosely.
[Resources]

Frequently asked questions

What are May temperatures in Rock Island?

An average high-temperature, in May, in Rock Island, is 66°F (18.9°C) and the average low-temperature is 43.3°F (6.3°C).

What is the average humidity in May in Rock Island?

In May, the average relative humidity is 57%.

How many days does it rain in May in Rock Island?

In Rock Island, in May, it is raining for 10.8 days, with typically 1.18" (30mm) of accumulated precipitation.

When it does not snow in Rock Island?

May through August and October are months without snowfall in Rock Island.

Does it snow in Rock Island 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 Rock Island?

In May, the average day length is 15h and 8min.

When are sunrise and sunset in May in Rock Island?

In May, on the first day of the month, sunrise is at 5:42 am and sunset at 8:12 pm. On the last day of the month, in Rock Island, Washington, sunrise is at 5:07 am and sunset at 8:49 pm PDT.

How long on average sun shines in May in Rock Island?

The average sunshine duration in May in Rock Island is 11h.

What is the UV index intensity in May in Rock Island?

The average daily maximum UV index in May in Rock Island is 5. A UV Index reading of 3 to 5 represents a medium hazard to health 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 May
Rock Island, WA

Average temperature in May - Rock Island, WA
  • Average high temperature in May: 66°F

The warmest month (with the highest average high temperature) is July (83.1°F).
The month with the lowest average high temperature is December (32.4°F).

  • Average low temperature in May: 43.3°F

The month with the highest average low temperature is August (56.3°F).
The coldest month (with the lowest average low temperature) is December (20.7°F).

[Resources]

Average pressure in May
Rock Island, WA

Average pressure in May - Rock Island, WA
  • Average pressure in May: 29.96"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is August (29.93"Hg).

[Resources]

Average wind speed in May
Rock Island, WA

Average wind speed in May - Rock Island, WA
  • Average wind speed in May: 6mph

The windiest month (with the highest average wind speed) is June (6.5mph).
The calmest month (with the lowest average wind speed) is December (3.7mph).

[Resources]

Average humidity in May
Rock Island, WA

Average humidity in May - Rock Island, WA
  • Average humidity in May: 57%

The month with the highest relative humidity is January (88%).
The months with the lowest relative humidity are July and August (44%).

[Resources]

Average rainfall in May
Rock Island, WA

Average rainfall in May - Rock Island, WA
  • Average rainfall in May: 1.18"

The wettest months (with the highest rainfall) are January and December (1.57").
The driest months (with the least rainfall) are July and August (0.24").

[Resources]

Average rainfall days in May
Rock Island, WA

Average rainfall days in May - Rock Island, WA
  • Average rainfall days in May: 10.8 days

The month with the highest number of rainy days is March (13.8 days).
The month with the least rainy days is August (3.8 days).

[Resources]

Average snowfall in May
Rock Island, WA

Average snowfall in May - Rock Island, WA
  • Average snowfall in May: 0"

The month with the highest snowfall is December (5.98").
The months with the least snowfall are May, June, July, August and October (0").

[Resources]

Average snowfall days in May
Rock Island, WA

Average snowfall days in May - Rock Island, WA
  • Average snowfall days in May: 0 days

The month with the highest number of snowfall days is December (9.5 days).
The months with the least snowfall days are May, June, July, August and October (0 days).

[Resources]

Average daylight in May /
Average sunshine in May
Rock Island, WA

Average daylight in May / Average sunshine in May - Rock Island, WA
  • Average daylight in May: 15h and 1min

The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).

  • Average sunshine in May: 11h and 0min

The month with the most sunshine is August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).

[Resources]

Average sunshine days in May
Rock Island, WA

Average sunshine days in May - Rock Island, WA
  • Average sunshine days in May: 18.1 days

The month with the most sunshine days is July (25.5 days).
The month with the least sunshine days is February (12.6 days).

[Resources]

Average UV index in May
Rock Island, WA

Average UV index in May - Rock Island, WA
  • Average UV index in May: 5

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).

[Resources]

Average cloud cover in May
Rock Island, WA

Average cloud cover in May - Rock Island, WA
  • Average cloud cover in May: 26

The month with the most cloud cover is January (Cloud cover 49).
The months with the least cloud cover are July and August (Cloud cover 11).

[Resources]

Average visibility in May
Rock Island, WA

Average visibility in May - Rock Island, WA
  • Average visibility in May: 6mi

The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (4mi).

[Resources]

Rock Island, Washington, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location