Does Williams Bay need sun protection in winter?

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

Can you burn on a cool day in Williams Bay?

Yes. UV is not heat. A cool, windy or lightly cloudy day in Williams Bay can still sit at UV 3 or above, especially from spring through autumn. Temperature on this page is for context only; the UV number is what decides protection.

UV index in Williams Bay today

Inland Williams Bay (WI) is 42.6° south. Without sea haze, January UV commonly runs 8–10 (very high), and a cool morning is no reason to skip sunscreen. 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 Williams Bay

Peak UV, temperature and conditions for Williams Bay. 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 day in Williams Bay can still sit at protection levels. Why you burn on cloudy days.

When Williams Bay needs sun protection

Sun protection is needed in Williams Bay typically from May through September, and any clear spring or fall day UV reaches 3. Inland heat or a cool change does not change the UV index; go by the number, not how the day feels.

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

Frequently asked questions

When does Williams Bay need sun protection?: Whenever the UV index is 3 or above. In Williams Bay 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 Williams Bay need sun protection in winter?: Not every day. Midwinter middays in Williams Bay often sit below UV 3, but clear late-winter and early-spring days cross the threshold before summer fully arrives. Check the live index.
Can you burn on a cool day in Williams Bay?: Yes. UV is not heat. A cool, windy or lightly cloudy day in Williams Bay can still sit at UV 3 or above, especially from spring through autumn. Temperature on this page is for context only; the UV number is what decides protection.