nomadseason

October Weather in Portland, United States

Last updated: June 24, 2025

In Portland, United States, the average temperature in October hovers around 17°C (63°F), offering a mild climate. Expect minimums as low as 0°C (33°F) and maximums reaching 36°C (98°F), providing a range of experiences for visitors. With an average precipitation of 138 mm (5.4 in) spread over 10 days, it's wise to prepare for some wet weather. Additionally, the air is generally humid, with an average humidity of 78%, creating a lush environment throughout the month.

October Temperature in Portland

In October in Portland, the average temperature is 17°C (63°F). Maximum temperatures can reach 36°C (98°F), while minimum temperatures can drop as low as 0°C (33°F). This makes Portland a great destination for travelers looking to experience a wide range of temperatures and outdoor activities.

October Weather in Portland: Daily Temperature Highs, Lows, and Averages

The chart illustrates October temperature patterns in Portland, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Portland, October typically has an average temperature of 17°C (63°F), with highs reaching up to 36°C (98°F) and lows dropping to around 0°C (33°F).
JanFebMarAprMayJunJulAugSepOctNovDec404452597076807873634845
Data source: Temperature data for Portland generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

October Precipitation in Portland

In Portland in October, the precipitation amount is 138 mm (5.4 in) over a span of 10 days.

October Precipitation Trends in Portland

The chart displays monthly precipitation patterns in Portland, with values for each month alongside October’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how October’s conditions compare to those of other months. In Portland, October typically receives around 138 mm (5.4 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec10518515715012214112512412513888147
Data source: Precipitation data for October generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

October Humidity in Portland

In Portland in October, humidity is 78%. With an average temperature of 17°C (63°F), this humidity feels like a warm, enveloping blanket, making traveling slightly uncomfortable as you navigate the sticky air, prompting the need for frequent breaks in cooler, shaded areas.

October Average Humidity in Portland

This chart illustrates the average monthly humidity levels in Portland, with October’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In October, average humidity in Portland is approximately 78%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%86%86%82%83%83%80%74%71%78%88%88%
Data source: Humidity data for October generated using information from the Copernicus Climate Change Service.

October UV Index in Portland

In Portland in October, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Portland.

Maximum UV Index Levels in Portland for October

The chart shows the monthly maximum UV Index (UVI) for Portland in October, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In October, the maximum UV index in Portland typically reaches 7, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec36710101111109753
Data source: Portland October UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How October Weather in Portland Compares to Other Months

Weather in Portland varies notably across the year, with each month offering distinct climate conditions. This page compares October’s weather to other months in Portland, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Portland, showing how October’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather4°C (40°F)105 mm (4.1 inches)87%moderate
February Weather7°C (44°F)185 mm (7.3 inches)86%high
March Weather11°C (52°F)157 mm (6.2 inches)86%high
April Weather15°C (59°F)150 mm (5.9 inches)82%very high
May Weather21°C (70°F)122 mm (4.8 inches)82%very high
June Weather25°C (77°F)141 mm (5.5 inches)83%extreme
July Weather27°C (80°F)125 mm (4.9 inches)80%extreme
August Weather25°C (78°F)124 mm (4.9 inches)74%very high
September Weather23°C (74°F)125 mm (4.9 inches)71%very high
October Weather17°C (63°F)138 mm (5.4 inches)78%high
November Weather9°C (48°F)88 mm (3.4 inches)88%moderate
December Weather7°C (45°F)147 mm (5.8 inches)88%moderate

Compare Portland's Climate with Cities Worldwide