UV Index in Portland, United States

Last updated: June 2, 2025

In Portland, United States, awareness of the UV Index is crucial for protecting your skin and maintaining overall health. Understanding UV levels can help you prevent sunburn and reduce the risk of long-term skin damage. With Portland's temperate climate, characterized by mild summers, it’s easy to underestimate UV exposure; however, peak UV levels can reach as high as 10 around midday. This means that even on seemingly overcast days, staying informed about UV risks is essential for enjoying the outdoors safely. So, whether you're hiking in the stunning Columbia River Gorge or relaxing at a local park, knowing the UV Index can help you savor the beauty of Portland while safeguarding your skin!

Hourly UV Index in Portland

As the sun rises, the UV Index gradually climbs, beginning at a mild 1 at 7:00 AM. By 9:00 AM, it reaches 3, prompting early risers to consider sun protection. The intensity peaks at 1:00 PM with a maximum of 10, signaling the most hazardous conditions for unprotected skin. As the afternoon unfolds, the index dips from 9 at 2:00 PM to 6 by 4:00 PM, offering a brief respite. As the day winds down, the UV rays decrease, falling to 2 by 6:00 PM and returning to a safe 1 by 7:00 PM. Stay mindful of these fluctuations to enjoy the sun while safeguarding your skin!

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
10:005moderate30 min
11:007high25 min
12:009very high15 min
13:0010very high15 min
14:009very high15 min
15:008very high15 min
16:006high25 min
17:004moderate30 min
18:002low45 min
19:001low45 min

Monthly UV Index Trends in Portland

Throughout the year, UV Index levels show significant seasonal variation, indicating fluctuating sun exposure risks. January and December experience a low UV Index (2), with a burn time of 45 minutes, making them safer months for sun exposure. February to March sees a moderate increase, with indices of 3 to 5 and burn times dropping to 30 minutes, requiring some caution. April marks the transition to high risk, with an index of 6 and a burn time of only 25 minutes. The high-risk months are typically May through August, where UV levels soar to 9 or 10, necessitating protective measures such as sunscreen and clothing, as burn times plummet to 15 minutes. As summer wanes, the UV Index decreases to 7 in September and 5 in October, enabling safer outdoor activities. November continues the trend toward lower risk with a return to a moderate UV Index of 3. It is essential for visitors and residents to stay informed and adjust their sun protection strategies accordingly, particularly during the summer months when the risk of skin damage is at its highest.

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.
JanFebMarAprMayJunJulAugSepOctNovDec24569101087532
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
Portland23569101087532
Chicago UVI34689101098642
Brooklyn UVI35681010998642
New York City UVI35681010998642
Los Angeles UVI46891011111010754
Houston UVI589111112121110975