Can a smartwatch measure UV exposure directly?

Most smartwatches display UV index from weather data, not direct measurement. Some UV clip-on sensors exist that measure personal UV dose, but wrist-based watches rely on location-based weather data.

What UV index requires sunscreen?

The WHO recommends sun protection at UV index 3 and above. Dermatologists often recommend daily sunscreen regardless, as UV exposure adds up even on cloudy days.

Best UV Monitors for Sun Protection 2026