UV index in Boulder Brook today
Inland Boulder Brook (DE) is 39.8° 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 Boulder Brook
Peak UV, temperature and conditions for Boulder Brook. 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 Boulder Brook can still sit at protection levels. Why you burn on cloudy days.
When Boulder Brook needs sun protection
Sun protection is needed in Boulder Brook 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 Boulder Brook need sun protection?
- Whenever the UV index is 3 or above. In Boulder Brook 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 Boulder Brook need sun protection in winter?
- Not every day. Midwinter middays in Boulder Brook 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 Boulder Brook?
- Yes. UV is not heat. A cool, windy or lightly cloudy day in Boulder Brook 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.