UV Index in Portland, United States

Last updated: June 2, 2025

In Portland, United States, being aware of the UV Index is essential for safeguarding your skin and overall health. Understanding UV levels helps in preventing sunburns and reducing the risk of long-term skin damage, particularly during the peak hours of sunlight. Given Portland's Dfb climate—characterized by warm summers and cooler, cloudier seasons—exposure to UV radiation can still be significant, especially during sunny spells. From the mid-morning to early afternoon, UV levels can reach as high as 10, making awareness crucial for enjoying the outdoors safely. Stay informed and protect your skin while embracing all that Portland has to offer!

Hourly UV Index in Portland

The UV Index reaches its peak during the midday hours, showcasing a vibrant sun's intensity. Starting with a gentle 1 at 07:00, it gradually escalates to 3 by 08:00. As the day progresses, the index soars to 5 at 09:00, hitting 7 by 10:00. The real highlight occurs between 11:00 and 13:00, when it peaks at an impressive 10, urging everyone to take caution. Following this, the index begins a slow descent, dropping to 9 at 14:00 and gradually declining to 5 by 16:00. By 18:00, it reduces to 2, finally settling back at 1 by 19:00. This hourly data highlights the importance of sun safety during the peak hours of the day.

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
08:003moderate30 min
09:005moderate30 min
10:007high25 min
11:009very high15 min
12:0010very high15 min
13:0010very high15 min
14:009very high15 min
15:007high25 min
16:005moderate30 min
17:003moderate30 min
18:002low45 min
19:001low45 min

Monthly UV Index Trends in Portland

As the seasons change, the UV Index experiences notable fluctuations, influencing both visitor and resident safety. January and December boast a low UV Index of 2, allowing for extended exposure times of 45 minutes without significant risk. However, as we move into spring with February and March, the UV Index rises to 4 and 5 respectively, indicating a moderate risk with a burn time of just 30 minutes. The high-risk months arrive in April through August, with peak values of 9 and 10 during May and June, categorizing the exposure as very high and shortening safe sun exposure to as little as 15 minutes. September sees a slight decrease to a high index of 7, while October and November return to moderate levels. Visitors and residents should take precautionary measures during the higher UV months by seeking shade, wearing protective clothing, and using sunscreen regularly to minimize 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.
JanFebMarAprMayJunJulAugSepOctNovDec2457910987532
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
Portland2457910987532
Chicago UVI34689101098642
Brooklyn UVI35681010998642
New York City UVI35681010998642
Los Angeles UVI46891011111010754
Houston UVI589111112121110975