Great suggestions to avoid sunburn from the American Academy of Dermatology:
Seek shade when appropriate. The sun’s rays are strongest between 10 a.m. and 2 p.m. If your shadow appears to be shorter than you are, seek shade.
Wear protective clothing. Wear a long-sleeved shirt, pants, a wide-brimmed hat, and sunglasses wherever possible.
Generously apply a broad-spectrum, water-resistant sunscreen. The sunscreen should have a Sun Protection Factor (SPF) of 30 or more, and it should be applied to all exposed skin areas. “Broad spectrum” provides protection from both ultraviolet A (UVA) and ultraviolet B (UVB) rays. For maximum protection, reapply sunscreen approximately every two hours, even on cloudy days, and after swimming or sweating.
See link below for further details: