Does Mercer Island Town need sun protection in winter?

Not every day. Midwinter middays in Mercer Island Town often sit below UV 3, but clear late-winter and early-spring days cross the threshold before summer fully arrives. Check the live index.

Does the water make UV worse in Mercer Island Town?

It can. Sand and water reflect ultraviolet, so skin that is not covered (including under the chin and on the tops of feet) picks up extra dose on top of the direct sun. The live UV index on this page is the sky reading; reflection is on top of that.

UV index in Mercer Island Town today

Island Mercer Island Town (WA) sits at 47.6°S. Open water lifts the UV dose on top of a sky reading that commonly hits 8–10 (very high) in January. This is cool-temperate America: summer UV still climbs into the very high band, and spring arrives before the weather feels hot.

Live reading · data by Open-Meteo · reference monitoring by ARPANSA

Today and tomorrow in Mercer Island Town

Peak UV, temperature and conditions for Mercer Island Town. Tomorrow’s peak is the number to plan around if you’re heading out in the middle of the day.

Weather conditions right now

Cloud and rain cut heat more than they cut UV. A partly cloudy island day in Mercer Island Town can still sit at protection levels. Why you burn on cloudy days.

When Mercer Island Town needs sun protection

Sun protection is needed in Mercer Island Town typically from May through September, and any clear spring or fall day UV reaches 3. With water on more than one side, reflection is the default, not a beach-only problem.

The threshold, per SunSmart and ARPANSA: whenever UV reaches 3 or above, Slip on covering clothing, Slop on SPF 50+ sunscreen, Slap on a hat, Seek shade and Slide on sunglasses. Read the full sun safety guide.

The UV scale at a glance

0–2Low
3–5Moderate
6–7High
8–10Very high
11+Extreme

Local support in Washington

Cancer Council WA: West Australian sun-safety campaigns and SunSmart schools.

Frequently asked questions

When does Mercer Island Town need sun protection?: Whenever the UV index is 3 or above. In Mercer Island Town that is typically from May through September, and any clear spring or fall day UV reaches 3. The EPA Sun Safety action steps apply at the same threshold used worldwide.
Does Mercer Island Town need sun protection in winter?: Not every day. Midwinter middays in Mercer Island Town often sit below UV 3, but clear late-winter and early-spring days cross the threshold before summer fully arrives. Check the live index.
Does the water make UV worse in Mercer Island Town?: It can. Sand and water reflect ultraviolet, so skin that is not covered (including under the chin and on the tops of feet) picks up extra dose on top of the direct sun. The live UV index on this page is the sky reading; reflection is on top of that.