Portland
Oregon, USA
Long-term weather forecast
Long-term weather forecast

August weather forecast and climate
Portland, OR

A colorful autumn view of the outline of Portland City, Oregon, with mountains in the distance
A colorful autumn view of the outline of Portland City, Oregon, with mountains in the distance
August is the warmest month of the year in Portland, Oregon, when the average temperatures peak at 81.1°F (27.3°C). The pleasant and dry weather during the day chugs along with moderate temperatures during the night.
The sunshine lasts for 10 hours during the 14-hour long days, which gives ample time for visitors to explore Portland with rare light showers during the day.
Light summer clothing is preferable in August, such as t-shirts, sweatshirts, and shorts. It is prudent to avoid the sun rays during midday when their intensity is at the peak.

What is the warmest month in Portland?

The warmest month in Portland is August, with an average high-temperature of 81.1°F (27.3°C) and an average low-temperature of 57.9°F (14.4°C).

What is the temperature in August in Portland?

In August, in Portland, Oregon, the average high-temperature is 81.1°F (27.3°C), and the average low-temperature is 57.9°F (14.4°C). In August, the average heat index (a.k.a. 'felt air temperature', 'feels like'), that combines relative humidity and air temperature, is calculated to 84°F (28.9°C).

What is the average humidity in August in Portland?

In Portland, Oregon, the average relative humidity in August is 64.8%.

How many days does it rain in August in Portland?

In August, the rain falls for 3.9 days. Throughout August, 0.7" (17mm) of precipitation is accumulated.

When it does not snow in Portland?

April through October are months without snowfall in Portland, Oregon.

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

The average length of the day in August in Portland is 14h.

How long on average sun shines in August in Portland?

The average sunshine in August in Portland, Oregon, is 9.6h.

What is the UV index reading in August in Portland?

In August, the average daily maximum UV index in Portland is 7. A UV Index of 6 to 7 symbolizes a high health threat from unprotected exposure to the UV radiation.
Average temperature in August - Portland, OR
  • Average high temperature in August: 81.1°F

The warmest month (with the highest average high temperature) is August (81.1°F).
The month with the lowest average high temperature is December (45.6°F).

  • Average low temperature in August: 58°F

The month with the highest average low temperature is August (58°F).
The coldest month (with the lowest average low temperature) is December (35.2°F).

Average humidity in August - Portland, OR
  • Average humidity in August: 64.8%

The month with the highest relative humidity is December (82.7%).
The month with the lowest relative humidity is July (62.8%).

Average rainfall in August - Portland, OR
  • Average rainfall in August: 0.7"

The wettest month (with the highest rainfall) is November (5.6").
Driest months (with the lowest rainfall) are July and August (0.7").

Average rainfall days in August - Portland, OR
  • Average rainfall days in August: 3.9 days

The month with the highest number of rainy days is November (19 days).
The month with the lowest number of rainy days is August (3.9 days).

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

The month with the highest snowfall is February (2.1").
Months with the lowest snowfall are April, May, June, July, August, September and October (0").

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

Months with the highest number of snowfall days are February and December (1.5 days).
Months with the lowest number of snowfall days are April, May, June, July, August, September and October (0 days).

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

The month with the longest days is June (Average daylight: 15.6h).
The month with shortest days is December (Average daylight: 8.8h).

  • Average sunshine in August: 9.6h

The month with most sunshine is July (Average sunshine: 10.7h).
The month with least sunshine is December (Average sunshine: 2.1h).

Average UV index in August - Portland, OR
  • Average UV index in August: 7

The month with the highest UV index is July (UV index 8).
Months with the lowest UV index are January and December (UV index 1).