UV Index in Portland, United States

Last updated: May 3, 2025

In Portland, understanding the UV Index is crucial for protecting your skin health and preventing sunburn. As a city located in a Dfb climate zone, Portland experiences varying UV exposure levels throughout the day, peaking during midday hours when the index can soar to 8. With the risk of skin damage on the rise, it's vital for residents and visitors alike to stay informed about UV levels and take appropriate precautions, especially in the warm months when outdoor activities are abundant. By being aware of the UV Index, you can enjoy Portland’s beautiful landscapes while keeping your skin safe!

Hourly UV Index in Portland

The UV Index throughout the day reveals a clear peak in sun intensity, providing a vivid illustration of solar exposure. Starting at 07:00, the index is a mild 1, indicating minimal risk. As the sun climbs higher, it rises to 3 by 09:00 and hits 6 at 11:00, urging early protectors to apply their sunscreen. The intensity reaches its zenith at 12:00, with a robust 7, and maintains 8 between 13:00 and 14:00, suggesting it's crucial to seek shade or cover during these hours. As the afternoon progresses, the figures gently decline, dipping to 4 at 17:00 and finally returning to a low 1 by 19:00. This hourly dance of the UV Index serves as a reminder to be sun-smart and make the most of outdoor activities while remaining vigilant during peak hours.

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
TimeUVICategoryTime to Burn
07:001low45 min
08:002low45 min
09:003moderate30 min
10:004moderate30 min
11:006high25 min
12:007high25 min
13:008very high15 min
14:008very high15 min
15:007high25 min
16:005moderate30 min
17:004moderate30 min
18:002low45 min
19:001low45 min

Monthly UV Index Trends in Portland

Throughout the year, the UV Index experiences notable fluctuations, impacting sun safety practices for both residents and visitors. From January to March, the UV levels are relatively low to moderate, with burn times ranging from 30 to 45 minutes. However, April marks the beginning of higher UV exposure, reaching a peak in May and June, where the index hits 9, classified as very high, and the burn time drops to just 15 minutes. July and August maintain these critical levels, posing significant risk for unprotected skin. September sees a decrease to a high index of 7, while October and November present moderate conditions again, allowing burn times of 30 minutes. By December, UV exposure returns to low levels. Visitors and residents are strongly advised to prioritize sun protection during the high-risk months of May through August, by applying sunscreen, seeking shade, and wearing protective clothing to minimize the risk of skin damage.

Monthly Maximum UV Index for Portland, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Portland. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec245789987432
Data source: Statistical UV Index data for Portland, based on 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.

Compare Portland UV Index with Other United States Cities

The table above highlights how UV exposure in Portland compares to other major locations across United States. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.
Portland's solar exposure compared to other cities in United States. Generated using Copernicus Atmosphere Monitoring Service information.
 JanFebMarAprMayJunJulAugSepOctNovDec
Portland245789987432
Chicago UVI34689101098642
Brooklyn UVI35681010998642
New York City UVI35681010998642
Los Angeles UVI46891011111010754
Houston UVI589111112121110975