Climate Insights for Portland

The climate in Portland is warm and mild. The average annual temperature is 23°C and approximately 818mm of precipitation falls per year. June is the wettest month, receiving around 104mm of rainfall. Portland is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: August, July, June. The coldest months are January, February, December, when temperatures can drop to 11°C.

Temperatures in Portland vary considerably across the year, with a 21°C difference between the coldest and warmest months. The warmest month is August, when average highs reach 32°C and the mean temperature sits around 29°C. January is the coolest month, with minimum temperatures around 11°C and an average of 14°C. Daily temperature variation is modest, with an average difference of 7°C between highs and lows. The sharpest temperature change occurs between October and November, with a 5°C shift in average temperatures.

Portland is a moderately rainy area, receiving approximately 818mm of precipitation annually, which averages out to around 68mm per month. The wettest month is June, averaging 104mm of rainfall. September and May also tend to see above-average precipitation. The driest month is February, with just 19mm. That's 85mm less than June, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.

Portland is mildly breezy, with an average annual wind speed of 17km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is April, averaging 20km/h, though still comfortable for most outdoor activities. The calmest conditions occur in September, with average winds dropping to 14km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 6km/h gap between the calmest and windiest months.

It is currently summer in Portland, which began on June 21, 2026. Portland is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in August at around 32°C, while the coldest stretch bottoms out in January near 11°C. Autumn is next, beginning on September 23, 2026 (9 days from now).

The best time to visit Portland is during February, March, April, October, November and December, when the weather is most comfortable for travellers. During these months, average temperatures hover around 20°C with modest rainfall averaging 50mm per month. By contrast, August can be uncomfortably hot with highs reaching 32°C, while January is the coldest period with lows dropping to 11°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.

The table below shows monthly climate averages for Portland based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.