UV Index in Northwest, United States

Last updated: June 2, 2025

Staying informed about the UV Index is crucial for residents in the Northwest United States, where varying terrain and weather can affect sun exposure. Understanding UV levels is essential not only for preventing painful sunburns but also for safeguarding long-term skin health. Despite its often overcast skies, the Northwest can present significant UV risks, especially during midday when the UV Index peaks at levels reaching 11—a potent reminder that harmful rays can penetrate even cloud cover. By being aware of the UV Index, you can enjoy the beautiful outdoors while protecting your skin.

Hourly UV Index in Northwest

The UV Index data showcases a dynamic day of sun exposure, starting gently at 1 around 7:00 AM and gradually climbing to a peak of 11 by 1:00 PM. As the sun rises higher, you'll feel the intensity ramp up, reaching a maximum of 10 between 12:00 PM and 1:00 PM, signaling the importance of protecting your skin. However, as the afternoon wears on, the UV Index begins to decrease, dropping to 6 by 4:00 PM and further cooling to 1 again by 7:00 PM. This pattern highlights a crucial window for sun protection from 10:00 AM to 2:00 PM, when UV exposure is at its most dangerous. Enjoy the sun, but remember to stay safe!

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	3	moderate	30 min
10:00	5	moderate	30 min
11:00	8	very high	15 min
12:00	10	very high	15 min
13:00	11	extreme	10 min
14:00	10	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

Monthly UV Index Trends in Northwest

Throughout the year, UV index values fluctuate significantly, with peaks during the summer months. From January to March, the UV index rises from a moderate level of 4 to a very high 8, indicating an increasing risk for skin damage. The high-risk months are clearly identified as May through July, with an extreme index of 11, where the burn time shortens to just 10 minutes. This intensity decreases slightly in August and September but remains very high at 10 and 9, respectively. As the year closes, UV levels drop back to moderate levels by December. Visitors and residents should take precautions during the high-risk months by using sunscreen, wearing protective clothing, and seeking shade to minimize the risk of sunburn and long-term skin damage.

Monthly Maximum UV Index for Northwest, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Northwest. 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 Northwest, 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 Northwest UV Index with Other United States Cities

The table above highlights how UV exposure in Northwest 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.

Northwest'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
Los Angeles UVI	4	6	8	9	10	11	11	10	10	7	5	4
Northwest	4	6	8	10	11	11	11	10	9	8	6	4
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5