When does San Juan need sun protection?

Whenever the UV index is 3 or above. In San Juan that is most of the year, including many winter middays. The EPA Sun Safety action steps apply at the same threshold used worldwide.

Does San Juan need sun protection in winter?

Usually yes. At 26.2°N, winter middays in San Juan still commonly reach UV 3 or higher. Check today's live reading on this page before a long lunch outside.

Can you burn on a cool day in San Juan?

Yes. UV is not heat. A cool, windy or lightly cloudy day in San Juan 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 San Juan today

San Juan in Texas sits inland at 26.2°S, where dry air and fewer clouds often mean harsher UV than the temperature suggests. Summer middays typically reach 11–13 (extreme). This is subtropical sun: protection weather for much of the year, with winter middays that still often reach 3 or more.

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

Today and tomorrow in San Juan

Peak UV, temperature and conditions for San Juan. 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 San Juan can still sit at protection levels. Why you burn on cloudy days.

When San Juan needs sun protection

Sun protection is needed in San Juan most of the year, including many winter middays. 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 San Juan need sun protection?: Whenever the UV index is 3 or above. In San Juan that is most of the year, including many winter middays. The EPA Sun Safety action steps apply at the same threshold used worldwide.
Does San Juan need sun protection in winter?: Usually yes. At 26.2°N, winter middays in San Juan still commonly reach UV 3 or higher. Check today's live reading on this page before a long lunch outside.
Can you burn on a cool day in San Juan?: Yes. UV is not heat. A cool, windy or lightly cloudy day in San Juan 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.