UV Index in Seattle, United States

Last updated: May 3, 2025

In Seattle, awareness of the UV Index is crucial for protecting your skin from harmful ultraviolet radiation. Understanding UV levels helps prevent sunburn and promotes better skin health, ensuring you enjoy the outdoors safely. Despite its reputation for cloudy weather, Seattle's climate can still present significant UV exposure risks, particularly during midday hours when the UV Index climbs to levels 6 to 8. Being informed about the UV Index not only keeps you sun-safe but also enhances your overall well-being in this beautiful Pacific Northwest city.

Hourly UV Index in Seattle

The UV Index throughout the day showcases a gradual rise in intensity, peaking at 8 between 1 PM and 2 PM, making this the most critical time for sun exposure. Starting the morning with a low index of 1 at 7 AM, the values steadily increase as the sun climbs higher; by 10 AM, it reaches 5, indicating moderate sun strength. As the sun continues its ascent, the index climbs to 6 at 11 AM and further escalates to 7 at noon, urging sun safety precautions. After hitting the afternoon high of 8, the index tapers off, dropping to 6 by 3 PM, before gradually descending to 1 by 7 PM. This daily cycle emphasizes the importance of protective measures during midday hours when the UV rays are at their strongest.

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
08:002low45 min
09:003moderate30 min
10:005moderate30 min
11:006high25 min
12:007high25 min
13:008very high15 min
14:008very high15 min
15:006high25 min
16:005moderate30 min
17:003moderate30 min
18:002low45 min
19:001low45 min

Monthly UV Index Trends in Seattle

As the seasons change, so do UV levels, significantly impacting sun exposure and skin safety for visitors and residents. January to March sees a gradual increase in UV Index, peaking with a moderate level in March at 5, where the burn time decreases to 30 minutes. The high-risk months, characterized by extremely high levels of UV radiation, are May through August, with indices soaring to 9 and enforcing a burn time of just 15 minutes. Following this, September presents a moderate risk with an index of 7, and a burn time of 25 minutes, before dropping again in October with a moderate index of 5. November and December then return to lower risks, emphasizing a UV Index of 2 and 1, respectively, allowing for longer safe exposure times of 45 minutes. To minimize the risk of UV-related harm, visitors and residents should take extra precautions during the high-risk months by wearing sunscreen, protective clothing, and limiting sun exposure during peak hours.

Monthly Maximum UV Index for Seattle, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Seattle. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec235689987421
Data source: Statistical UV Index data for Seattle, 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 Seattle UV Index with Other United States Cities

The table above highlights how UV exposure in Seattle 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.
Seattle's solar exposure compared to other cities in United States. Generated using Copernicus Atmosphere Monitoring Service information.
 JanFebMarAprMayJunJulAugSepOctNovDec
Seattle235689987521
Chicago UVI34689101098642
Brooklyn UVI35681010998642
New York City UVI35681010998642
Los Angeles UVI46891011111010754
Houston UVI589111112121110975