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!
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!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 9 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 9 | very high | 15 min |
| 15:00 | 8 | very high | 15 min |
| 16:00 | 6 | high | 25 min |
| 17:00 | 4 | moderate | 30 min |
| 18:00 | 2 | low | 45 min |
| 19:00 | 1 | low | 45 min |
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.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Portland | 2 | 3 | 5 | 6 | 9 | 10 | 10 | 8 | 7 | 5 | 3 | 2 |
| Chicago UVI | 3 | 4 | 6 | 8 | 9 | 10 | 10 | 9 | 8 | 6 | 4 | 2 |
| Brooklyn UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| New York City UVI | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 9 | 8 | 6 | 4 | 2 |
| Los Angeles UVI | 4 | 6 | 8 | 9 | 10 | 11 | 11 | 10 | 10 | 7 | 5 | 4 |
| Houston UVI | 5 | 8 | 9 | 11 | 11 | 12 | 12 | 11 | 10 | 9 | 7 | 5 |