When does San Antonio need sun protection?

Whenever the UV index is 3 or above. In San Antonio 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 Antonio need sun protection in winter?

Usually yes. At 29.4°N, winter middays in San Antonio still commonly reach UV 3 or higher. Check today's live reading on this page before a long lunch outside.

Does city shade protect you from UV in San Antonio?

Only while you stay in it. Buildings cut some sky, but plazas, crossings and glass bounce UV onto uncovered skin. The live index on this page is the open-sky reading. Treat lunch outside as full-sun time whenever it is 3 or above.

UV index in San Antonio today

San Antonio (TX) is an urban UV pocket at 29.4°S. Office-to-café stretches add up, and typical summer peaks of 10–12 (very high to extreme) hit the same skin that feels 'just popping out'. 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 Antonio

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

When San Antonio needs sun protection

Sun protection is needed in San Antonio most of the year, including many winter middays. A shaded laneway is not a shaded day: step into a plaza or the commute and the index is the one on this page.

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 Antonio need sun protection?: Whenever the UV index is 3 or above. In San Antonio 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 Antonio need sun protection in winter?: Usually yes. At 29.4°N, winter middays in San Antonio still commonly reach UV 3 or higher. Check today's live reading on this page before a long lunch outside.
Does city shade protect you from UV in San Antonio?: Only while you stay in it. Buildings cut some sky, but plazas, crossings and glass bounce UV onto uncovered skin. The live index on this page is the open-sky reading. Treat lunch outside as full-sun time whenever it is 3 or above.