August weather forecast
Portland, OR

A colorful autumn view of the outline of Portland City, Oregon, USA
A colorful autumn view of the outline of Portland City, Oregon, USA

Weather in August

The last month of the summer, August, is another warm month in Portland, Oregon, with temperature in the range of an average low of 55°F (12.8°C) and an average high of 81.5°F (27.5°C).

Temperature

With an average high-temperature of 81.5°F (27.5°C) and an average low-temperature of 55°F (12.8°C), August is the warmest month.

Heat index

The average heat index in August is appraised at 84.2°F (29°C). Exhaustion is likely with prolonged exposure and activity. Sustaining activity may result in heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature', 'real feel', 'felt air temperature', or 'feels like', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. Additional factors like activity, pregnancy, metabolic differences, and wind affect individual temperature impact. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.

Humidity

The least humid month in Portland is August, with an average relative humidity of 63%.

Rainfall

In August, the rain falls for 5.2 days. Throughout August, 0.39" (10mm) of precipitation is accumulated. Throughout the year, in Portland, Oregon, there are 173.1 rainfall days, and 31.18" (792mm) of precipitation is accumulated.

Snowfall

April through October are months without snowfall in Portland.

Daylight

The average length of the day in August in Portland is 14h and 3min.
On the first day of August in Portland, sunrise is at 5:55 am and sunset at 8:39 pm. On the last day of the month, sunrise is at 6:31 am and sunset at 7:50 pm PDT.

Sunshine

The month with the most sunshine in Portland is August, with an average of 10.9h of sunshine.

UV index

In Portland, Oregon, the average daily maximum UV index in August is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the ordinary person.
Note: In August, the average maximum UV index of 5 translate into the following recommendations:
Take precautions - Protection against sun damage is advised. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.
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FAQ

What is the warmest month in Portland?

The warmest month in Portland, Oregon, is August, with an average high-temperature of 81.5°F (27.5°C) and an average low-temperature of 55°F (12.8°C).

What is the temperature in August in Portland?

In Portland, in August, the average high-temperature is 81.5°F (27.5°C), and the average low-temperature is 55°F (12.8°C). The average heat index (a.k.a. 'feels like', 'real feel'), which calculates the temperature value influenced by the moisture in the air, in August is appraised at 84.2°F (29°C).

What is the least humid month in Portland?

The least humid month in Portland is August, with an average relative humidity of 63%.

What is the average humidity in August in Portland?

The average relative humidity in August is 63%.

How much does it rain in Portland in August?

In August, the rain falls for 5.2 days. Throughout August, 0.39" (10mm) of precipitation is accumulated.

When it does not snow in Portland?

In Portland, snow does not fall in April through October.

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

In August, the average day length in Portland is 14h and 3min.

What time are sunrise and sunset in August in Portland?

On the first day of August, sunrise is at 5:55 am and sunset at 8:39 pm. On the last day of the month, sunrise is at 6:31 am and sunset at 7:50 pm PDT.

What month has the most sunshine in Portland?

The month with the most sunshine is August, with an average of 10.9h of sunshine.

How long on average sun shines in August in Portland?

The average sunshine duration in August in Portland is 10.9h.

How high is the UV index in August in Portland?

The average daily maximum UV index in August in Portland is 5. A UV Index estimate of 3 to 5 represents a moderate vulnerability from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in August
Portland, OR

Average temperature in August - Portland, OR
  • Average high temperature in August: 81.5°F

The warmest month (with the highest average high temperature) is August (81.5°F).
The month with the lowest average high temperature is December (44.1°F).

  • Average low temperature in August: 55°F

The month with the highest average low temperature is August (55°F).
The coldest month (with the lowest average low temperature) is December (34.7°F).

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Average pressure in August
Portland, OR

Average pressure in August - Portland, OR
  • Average pressure in August: 30"Hg

The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).

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Average wind speed in August
Portland, OR

Average wind speed in August - Portland, OR
  • Average wind speed in August: 3.9mph

The windiest month (with the highest average wind speed) is January (5.8mph).
The calmest month (with the lowest average wind speed) is August (3.9mph).

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Average humidity in August
Portland, OR

Average humidity in August - Portland, OR
  • Average humidity in August: 63%

The months with the highest relative humidity are January, February and December (83%).
The month with the lowest relative humidity is August (63%).

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Average rainfall in August
Portland, OR

Average rainfall in August - Portland, OR
  • Average rainfall in August: 0.39"

The wettest month (with the highest rainfall) is December (4.53").
The driest month (with the least rainfall) is July (0.31").

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Average rainfall days in August
Portland, OR

Average rainfall days in August - Portland, OR
  • Average rainfall days in August: 5.2 days

The month with the highest number of rainy days is March (20.4 days).
The month with the least rainy days is July (4.9 days).

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Average snowfall in August
Portland, OR

Average snowfall in August - Portland, OR
  • Average snowfall in August: 0"

The month with the highest snowfall is March (1.5").
The months with the least snowfall are April, May, June, July, August, September and October (0").

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Average snowfall days in August
Portland, OR

Average snowfall days in August - Portland, OR
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is February (2.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

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Average daylight in August /
Average sunshine in August
Portland, OR

Average daylight in August / Average sunshine in August - Portland, OR
  • Average daylight in August: 14h and 3min

The month with the longest days is June (Average daylight: 15h and 38min).
The month with the shortest days is December (Average daylight: 8h and 46min).

  • Average sunshine in August: 10h and 54min

The month with the most sunshine is August (Average sunshine: 10h and 54min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

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Average sunshine days in August
Portland, OR

Average sunshine days in August - Portland, OR
  • Average sunshine days in August: 23.8 days

The months with the most sunshine days are July and August (23.8 days).
The month with the least sunshine days is March (8.3 days).

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Average UV index in August
Portland, OR

Average UV index in August - Portland, OR
  • 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, November and December (UV index 2).

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Average cloud cover in August
Portland, OR

Average cloud cover in August - Portland, OR
  • Average cloud cover in August: 23

The month with the most cloud cover is February (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 23).

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Average visibility in August
Portland, OR

Average visibility in August - Portland, OR
  • Average visibility in August: 6mi

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

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