Last updated: July 2, 2025
Understanding the UV Index is crucial for everyone in Portland, Oregon. With significant UV radiation peaking during sunny months, being aware of UV levels can help prevent sunburn and protect your skin's health. The climate in Portland, categorized as Dfb, often features cloudy days mixed with bursts of sunlight, leading to varying UV exposure risks. Even on overcast days, UV rays can cause harm, making it essential to stay informed about daily UV Index levels, especially when they peak at 9 between 1 PM and 3 PM. Stay vigilant and safeguard your skin while enjoying the beautiful Portland outdoors!
Starting from 07:00 AM, the UV Index remains low at 1, perfect for a morning stroll. As the sun climbs higher, the intensity gradually increases: reaching 3 by 09:00 AM and then escalating to 4 at 10:00 AM. The peak intensity occurs at 01:00 PM, with a striking UV Index of 9, suggesting it's vital to seek shade or apply sunscreen during this hour. The afternoon sees a slight decline, with values of 8 at 03:00 PM and 6 by 04:00 PM. As the day winds down, the UV Index drops back to 4 at 05:00 PM, and then gently falls to 2 by 06:00 PM, before settling back at 1 near sunset. It's a day to stay sun-smart!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 4 | moderate | 30 min |
| 11:00 | 6 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 9 | 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, 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.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Portland | 2 | 4 | 5 | 7 | 8 | 9 | 9 | 8 | 7 | 4 | 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 |