May weather forecast
Mattawa, WA

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Weather in May

May, the last month of the spring in Mattawa, is an agreeable month, with temperature in the range of an average low of 49.1°F (9.5°C) and an average high of 71.2°F (21.8°C).

Temperature

With the onset of May, Mattawa's average high-temperature experiences a rise, moving from April's refreshing 61.3°F (16.3°C) to a pleasant 71.2°F (21.8°C). Mattawa experiences a significant downturn from peak daytime temperatures throughout May, with the average low-temperature dipping to a frosty 49.1°F (9.5°C).

Humidity

The average relative humidity in May is 48%.

Rainfall

In Mattawa, during May, the rain falls for 8.2 days and regularly aggregates up to 0.71" (18mm) of precipitation. In Mattawa, Washington, during the entire year, the rain falls for 86.4 days and collects up to 6.38" (162mm) of precipitation.

Snowfall

In Mattawa, snow does not fall in May through August and October.

Daylight

In Mattawa, the average length of the day in May is 15h and 4min.
On the first day of May, sunrise is at 5:43 am and sunset at 8:10 pm. On the last day of the month, sunrise is at 5:09 am and sunset at 8:45 pm PDT.

Sunshine

In May, the average sunshine is 11h.

UV index

In Mattawa, the average daily maximum UV index in May is 5. A UV Index of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for ordinary individuals.
Note: The daily high UV index of 5 in May translates into this advice:
Proceed with care. Light skin individuals may be exposed to burns in fewer than 30 minutes. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Enhance your sun protection with tightly woven, yet airy clothing.
Updated: Jun 29, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in May?

The high-temperature during May is 71.2°F (21.8°C) and the low-temperature is 49.1°F (9.5°C).

What is the average humidity in May?

The average relative humidity in May is 48%.

How much does it rain in May?

In Mattawa, during May, the rain falls for 8.2 days and regularly aggregates up to 0.71" (18mm) of precipitation.

When it does not snow in Mattawa?

May through August and 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 Mattawa?

In Mattawa, the average day length in May is 15h and 4min.

What time are sunrise and sunset in May?

In May, on the first day of the month, sunrise is at 5:43 am and sunset at 8:10 pm. On the last day of the month, sunrise is at 5:09 am and sunset at 8:45 pm PDT.

How long on average sun shines in May?

The average sunshine duration in May is 11h.

How high is the UV index in May?

In Mattawa, the average daily maximum UV index in May is 5. A UV Index estimate of 3 to 5 represents 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 May
Mattawa, WA

Average temperature in May - Mattawa, WA
  • Average high temperature in May: 71.2°F

The warmest months (with the highest average high temperature) are July and August (88.3°F).
The month with the lowest average high temperature is December (34.5°F).

  • Average low temperature in May: 49.1°F

The month with the highest average low temperature is August (61.5°F).
The coldest month (with the lowest average low temperature) is December (24.3°F).

Average pressure in May
Mattawa, WA

Average pressure in May - Mattawa, WA
  • Average pressure in May: 29.95"Hg

The month with the highest atmospheric pressure is January (30.17"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).

Average wind speed in May
Mattawa, WA

Average wind speed in May - Mattawa, WA
  • Average wind speed in May: 7.1mph

The windiest month (with the highest average wind speed) is April (7.6mph).
The calmest month (with the lowest average wind speed) is December (4.7mph).

Average humidity in May
Mattawa, WA

Average humidity in May - Mattawa, WA
  • Average humidity in May: 48%

The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is July (37%).

Average rainfall in May
Mattawa, WA

Average rainfall in May - Mattawa, WA
  • Average rainfall in May: 0.71"

The wettest months (with the highest rainfall) are January and December (0.87").
The driest month (with the least rainfall) is August (0.2").

Average rainfall days in May
Mattawa, WA

Average rainfall days in May - Mattawa, WA
  • Average rainfall days in May: 8.2 days

The month with the highest number of rainy days is March (10.6 days).
The month with the least rainy days is August (3.5 days).

Average snowfall in May
Mattawa, WA

Average snowfall in May - Mattawa, WA
  • Average snowfall in May: 0"

The month with the highest snowfall is December (3.43").
The months with the least snowfall are May, June, July, August and October (0").

Average snowfall days in May
Mattawa, WA

Average snowfall days in May - Mattawa, WA
  • Average snowfall days in May: 0 days

The month with the highest number of snowfall days is December (6.5 days).
The months with the least snowfall days are May, June, July and August (0 days).

Average daylight in May /
Average sunshine in May
Mattawa, WA

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

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: 11h and 0min

The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 54min).

Average sunshine days in May
Mattawa, WA

Average sunshine days in May - Mattawa, WA
  • Average sunshine days in May: 20.9 days

The months with the most sunshine days are July and August (25.8 days).
The month with the least sunshine days is February (16 days).

Average UV index in May
Mattawa, WA

Average UV index in May - Mattawa, WA
  • Average UV index in May: 5

The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in May
Mattawa, WA

Average cloud cover in May - Mattawa, WA
  • Average cloud cover in May: 25

The month with the most cloud cover is January (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 10).

Average visibility in May
Mattawa, WA

Average visibility in May - Mattawa, WA
  • Average visibility in May: 6mi

The months with the highest visibility are February, March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (5mi).

Mattawa, Washington, USA

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