August weather forecast
Umtanum, WA

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Weather in August

The last month of the summer, August, is another warm month in Umtanum, Washington, with an average temperature varying between 82°F (27.8°C) and 55.2°F (12.9°C).

Temperature

The warmest period is usually observed in July and August, with the average high-temperature peaking at 82°F (27.8°C).

Heat index

Throughout August, the heat index is evaluated at 82.4°F (28°C). If one endures exposure and continues to be active, it might result in tiredness and heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is an estimation of the warmth sensation when considering humidity levels. Factors such as metabolic variation, pregnancy, and physical activity play a role in one's impression of weather. The sun, when shining directly, can have a significant impact on the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Kids are usually in more danger than grown-ups as they tend to sweat less. Plus, their bigger skin surface in relation to their small frames and increased heat generation due to their activity level make them more susceptible.

Humidity

The months with the lowest humidity in Umtanum are July and August, with an average relative humidity of 46%.

Rainfall

In Umtanum, in August, it is raining for 2.8 days, with typically 0.24" (6mm) of accumulated precipitation. Throughout the year, in Umtanum, there are 99.9 rainfall days, and 8.66" (220mm) of precipitation is accumulated.

Snowfall

May through August are months without snowfall.

Daylight

The average length of the day in August is 14h and 9min.
On the first day of the month, sunrise is at 5:42 am and sunset at 8:33 pm. On the last day of August, in Umtanum, sunrise is at 6:21 am and sunset at 7:42 pm PDT.

Sunshine

The months with the most sunshine are July and August, with an average of 12h of sunshine.

UV index

The average daily maximum UV index in August in Umtanum is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the ordinary person.
Note: The maximum UV index, 5 during August, leads to the following recommendations:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What time of the year is the hottest in Umtanum?

Umtanum experiences the peak of its temperatures in July and August, when the average high-temperatures rise to 82°F (27.8°C).

What are the temperatures in Umtanum in August?

Umtanum in August has an average high-temperature of 82°F (27.8°C) and an average low-temperature of 55.2°F (12.9°C). In August, the average heat index (a.k.a. 'real feel', 'apparent temperature'), which calculates the temperature value influenced by the moisture in the air, is evaluated at 82.4°F (28°C).

What are the least humid months in Umtanum?

The months with the lowest humidity are July and August, with an average relative humidity of 46%.

What is the average humidity in August in Umtanum?

In August, the average relative humidity is 46%.

How many days does it rain in August in Umtanum?

In Umtanum, during August, the rain falls for 2.8 days and regularly aggregates up to 0.24" (6mm) of precipitation.

When it does not snow in Umtanum?

May through August are months without snowfall.

Does it snow in Umtanum in August?

In Umtanum, in August, it doesn't snow. In September, it regularly snows.

What is the average length of the day in August in Umtanum?

In August, the average day length in Umtanum is 14h and 9min.

What time are sunrise and sunset in August in Umtanum?

On the first day of August, sunrise is at 5:42 am and sunset at 8:33 pm. On the last day of the month, sunrise is at 6:21 am and sunset at 7:42 pm PDT.

What is the month with the most sunshine in Umtanum?

The months with the most sunshine are July and August, with an average of 12h of sunshine.

How many hours of sunshine does Umtanum have in August?

In August, the average sunshine duration in Umtanum, Washington, is 12h.

How high is the UV index in August in Umtanum?

In August, the average daily maximum UV index in Umtanum is 5. A UV Index reading of 3 to 5 represents 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 August
Umtanum, WA

Average temperature in August - Umtanum, WA
  • Average high temperature in August: 82°F

The warmest months (with the highest average high temperature) are July and August (82°F).
The month with the lowest average high temperature is December (33.3°F).

  • Average low temperature in August: 55.2°F

The month with the highest average low temperature is August (55.2°F).
The coldest month (with the lowest average low temperature) is December (21.4°F).

Average pressure in August
Umtanum, WA

Average pressure in August - Umtanum, WA
  • Average pressure in August: 29.94"Hg

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is August (29.94"Hg).

Average wind speed in August
Umtanum, WA

Average wind speed in August - Umtanum, WA
  • Average wind speed in August: 8.3mph

The windiest month (with the highest average wind speed) is June (8.9mph).
The calmest month (with the lowest average wind speed) is December (4.2mph).

Average humidity in August
Umtanum, WA

Average humidity in August - Umtanum, WA
  • Average humidity in August: 46%

The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are July and August (46%).

Average rainfall in August
Umtanum, WA

Average rainfall in August - Umtanum, WA
  • Average rainfall in August: 0.24"

The wettest month (with the highest rainfall) is December (1.3").
The driest month (with the least rainfall) is July (0.16").

Average rainfall days in August
Umtanum, WA

Average rainfall days in August - Umtanum, WA
  • Average rainfall days in August: 2.8 days

The month with the highest number of rainy days is March (12.4 days).
The month with the least rainy days is August (2.8 days).

Average snowfall in August
Umtanum, WA

Average snowfall in August - Umtanum, WA
  • Average snowfall in August: 0"

The month with the highest snowfall is December (4.65").
The months with the least snowfall are May, June, July and August (0").

Average snowfall days in August
Umtanum, WA

Average snowfall days in August - Umtanum, WA
  • Average snowfall days in August: 0 days

The months with the highest number of snowfall days are January and December (8.7 days).
The months with the least snowfall days are May, June, July and August (0 days).

Average daylight in August /
Average sunshine in August
Umtanum, WA

Average daylight in August / Average sunshine in August - Umtanum, WA
  • Average daylight in August: 14h 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 August: 12h and 0min

The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The months with the least sunshine are January and December (Average sunshine: 4h and 48min).

Average sunshine days in August
Umtanum, WA

Average sunshine days in August - Umtanum, WA
  • Average sunshine days in August: 26.8 days

The month with the most sunshine days is July (27.1 days).
The month with the least sunshine days is February (13.5 days).

Average UV index in August
Umtanum, WA

Average UV index in August - Umtanum, WA
  • Average UV index in August: 5

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

Average cloud cover in August
Umtanum, WA

Average cloud cover in August - Umtanum, WA
  • Average cloud cover in August: 11

The month with the most cloud cover is January (Cloud cover 48).
The months with the least cloud cover are July and August (Cloud cover 11).

Average visibility in August
Umtanum, WA

Average visibility in August - Umtanum, WA
  • Average visibility in August: 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).

Umtanum, Washington, USA

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