UV Index in Portland, United States

Last updated: June 2, 2025

Understanding the UV Index is crucial for residents of Portland, United States, as it helps you stay informed about the sun's intensity and protect your skin from potential harm. With Portland's climate experiences featuring warm summers and moderate exposure to sunlight, knowing the UV levels throughout the day can significantly aid in preventing sunburn and maintaining long-term skin health. During peak hours, particularly between 11:00 AM to 1:00 PM, UV levels can soar to as high as 10, underscoring the importance of vigilance. Stay aware, stay protected, and enjoy the great outdoors safely!

Hourly UV Index in Portland

As the day unfolds, the UV Index experiences a dramatic rise, peaking at an intense 10 around 1 PM, signaling the highest level of harmful UV radiation. Early morning hours start gently, with a maximum of 1 at 7 AM, gradually increasing to a moderate 4 by 9 AM. The ascent continues steadily, reaching a notable 8 between 11 AM and 12 PM before soaring to its zenith. After this peak, the index begins to wane, declining to 5 by 4 PM and dropping further to a safe 1 by 7 PM. It’s vital to stay protected during the peak hours of 11 AM to 3 PM to enjoy the sunshine without compromising skin health.

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.
Time	UVI	Category	Time to Burn
07:00	1	low	45 min
08:00	2	low	45 min
09:00	4	moderate	30 min
10:00	6	high	25 min
11:00	8	very high	15 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	5	moderate	30 min
17:00	3	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Portland

Throughout the year, UV exposure varies significantly, peaking during late spring and summer months. High-risk months for UV exposure are April through September, where the UV Index frequently reaches levels classified as very high; particularly notable are May, June, and July, when it consistently hits a maximum of 10. Visitors and residents are advised to take precautions during these months, with burn times dramatically reduced to as little as 15 minutes. In contrast, January, February, and November present moderate UV levels, and December has a low index, making sun safety measures less critical during these months. To protect against skin damage, it is essential to wear sunscreen, seek shade, and wear protective clothing, especially between peak months of April and September.

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.

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.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
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
Portland	3	5	6	9	10	10	10	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