Does San Jose need sun protection in winter?

Not every day. Midwinter middays in San Jose 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 city shade protect you from UV in San Jose?

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 Jose today

San Jose (CA) is an urban UV pocket at 37.3°S. Office-to-café stretches add up, and typical summer peaks of 9–11 (very high to extreme) hit the same skin that feels 'just popping out'. 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 San Jose

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

When San Jose needs sun protection

Sun protection is needed in San Jose typically from May through September, and any clear spring or fall day UV reaches 3. 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 Jose need sun protection?: Whenever the UV index is 3 or above. In San Jose 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 San Jose need sun protection in winter?: Not every day. Midwinter middays in San Jose 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 city shade protect you from UV in San Jose?: 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.