UV Index Today in Seattle, Washington
Seattle's UV Climate
Seattle, located in the Pacific Northwest, experiences a temperate marine climate with moderate UV exposure during the summer months. The city's northern latitude and frequent cloud cover reduce UV intensity compared to southern cities, but clear summer days can still bring high UV levels. Residents and visitors should use sun protection during outdoor activities, especially near water where reflection increases exposure.
Average Annual UV Index
4.8
Peak UV Season
June - September
Sunny Days per Year
152
Typical UV Index by Season in Seattle
| Season | Typical Midday UV | Protection Needed |
|---|---|---|
| Summer | High (6-8) | SPF 30+, hat, sunglasses; shade from 10 AM – 4 PM |
| Spring & Fall | Moderate (3-5) | SPF 30+ for extended time outdoors |
| Winter | Low (1) | Sunscreen for long midday exposure; more on snow |
UV Index in Nearby Cities
- UV Index in Portland, OR145 mi away
- UV Index in Spokane, WA228 mi away
- UV Index in Eugene, OR248 mi away
- UV Index in Boise, ID405 mi away
Practical Tips for Outdoor Activities
Make the most of outdoor activities while staying safe in King County:
- Check UV index and weather radar before planning outdoor activities
- Schedule outdoor activities during low UV hours
- Use appropriate sun protection based on UV levels
- Stay hydrated during outdoor activities
- Take regular breaks in shaded areas
- Monitor weather conditions for changes
- Be prepared for sudden weather changes
- Know the signs of heat-related illness
- Wear a hat and protective clothing
- Check visibility conditions before outdoor plans
- Stay alert to weather alerts and warnings
UV and Weather in King County
Learn about King County's unique climate patterns, UV radiation levels, and how they affect your daily life. Enter your zip code for location-specific weather radar data and UV forecasts to help you make informed decisions about outdoor activities and sun protection.
Climate and UV Patterns
Seattle's climate features mild, wet winters and cool, dry summers. UV index values are highest from late spring through early fall, with peak values reaching 7-8 on clear days. The marine influence moderates temperatures but does not significantly reduce UV exposure. Cloud cover is common, but when skies are clear, UV radiation can be intense.
UV Index and Health Impact
Understanding UV radiation levels is crucial for protecting your health. Typical clear-day UV index values in Seattle through the year:
- Summer: High (6-8)
- Spring/Fall: Moderate (3-5)
- Winter: Low (1)
- Peak UV hours: 10 AM - 4 PM
- Cloud cover can reduce UV by 20-40%, but does not eliminate it
- Clear skies bring maximum UV exposure
Local Weather Patterns
Seattle's weather is highly variable, with frequent changes in cloud cover and temperature. Summer brings the highest UV exposure, especially during midday hours. The presence of Puget Sound can increase UV reflection, making sun protection important for beachgoers and boaters. Winter UV levels are low but not negligible, especially on sunny, snowy days.
Frequently Asked Questions About UV in Seattle
What is the UV index in Seattle today?
The live UV index for Seattle, WA is shown at the top of this page and updates throughout the day, along with today's maximum and an hourly forecast.
When is the sun strongest in Seattle?
UV radiation is strongest between 10 AM and 4 PM. Seattle's peak UV season runs June - September, when the midday index typically reaches High (6-8).
How high does the UV index get in Seattle?
Summer days in Seattle typically reach High (6-8). Spring and fall usually bring Moderate (3-5), while winter values are typically Low (1).
Do I need sunscreen in Seattle during winter?
Winter UV in Seattle is usually low, so sunburn risk is limited on typical days. Sunscreen is still wise during midday hours or around reflective snow.
How sunny is Seattle compared to other cities?
Seattle averages about 152 sunny days per year with an average annual UV index around 4.8.