The American Academy of Dermatology recommends wearing a broad spectrum (effective against UVA and UVB), water resistant sunscreen with a SPF (Sun Protection Factor) of at least 30. Reapply at least every two hours.
Watch out for sun damage even when it’s cloudy. UVA and UVB rays easily penetrate clouds and haze.
Be aware that the sun’s rays are strongest between 10AM and 2PM. If possible, seek shade from direct exposure during those times.
Wear a wide-brimmed hat, sunglasses and protective clothing when out in the sun.