How to choose a sun hat for hiking

The right sun hat is one of the most cost-effective pieces of gear you can carry: it blocks UV, prevents heat exhaustion, and keeps sweat out of your eyes for the price of a tank of gas.

UPF ratings: what the number actually means

UPF (Ultraviolet Protection Factor) measures how much UV radiation a fabric blocks. A UPF 50 fabric blocks 98% of UV rays; UPF 30 blocks about 97%. That gap sounds small until you're on a high-elevation snowfield where UV intensity is 40–50% higher per 1,000 metres of elevation gain.

Fabric construction matters as much as the label. Tightly woven nylon and polyester hold their UPF rating when wet; loosely woven cotton and straw drop significantly once damp with sweat. If your hat gets soaked on a river crossing or a rain shower, a straw hat may offer surprisingly little protection until it dries.

Brim width and coverage: the numbers that matter

Brim width is the single most important variable in sun protection. Dermatologists recommend at least 3 inches (7.5 cm) of brim to adequately shade the face, ears, and the back of the neck. A standard baseball cap brim runs about 2.75 inches and leaves the ears and neck fully exposed.

For the nose and cheeks specifically, a front brim of 3.5–4 inches makes a measurable difference. The ears and back of the neck are the most common sites for sun-related skin damage in outdoor athletes, so a hat with a shorter or asymmetric brim is a real trade-off, not just an aesthetic one.

Ears and the back of the neck account for a disproportionate share of UV-related skin damage in hikers, yet most caps leave both fully exposed.

Style comparison: wide brim vs bucket vs cap with cape

Packability: bucket hats and legionnaire-style caps stuff into a jacket pocket. Stiff wide-brim hats do not, though many packable wide brims use flexible wire to reshape after folding. If you're moving in and out of a pack, test how a hat stores before buying.

Ventilation and moisture management

Heat builds under any hat. Look for mesh crown panels, like the one on the Tilley LTM6 Airflo, or laser-cut perforations in the crown, which allow convective airflow to carry heat away. A fully solid crown in nylon can raise head temperature noticeably on a climb, pushing people to remove the hat exactly when sun protection matters most.

Moisture-wicking sweatbands (typically a thin polyester or merino strip at the inner brim) prevent salt buildup and reduce brow drip. On long days, this matters more than most gear reviews acknowledge. Check that the sweatband is removable or at least washable.

Matching hat to terrain

Desert: Maximum coverage is the priority. A 4-inch stiff or packable wide brim in UPF 50+ nylon or polyester, like the Sunday Afternoons Ultra Adventure Hat. Light color (white, tan, light grey) reflects radiant heat rather than absorbing it. Chin strap useful as winds are common.

Forest and mixed cover: A bucket hat or a medium wide-brim (3 inches) is sufficient. Weight and packability matter more here since you'll be stowing the hat when under canopy.

Alpine and above-treeline: Wide brim or legionnaire. Chin strap is essential: gusts above 8,000–10,000 feet can exceed 40 mph on exposed ridges. Darker fabric is acceptable since radiant heat is less the concern than UV at altitude and snow glare. Consider a hat compatible with wearing a helmet over it if scrambling.

River and water: A bucket hat with a hydrophilic liner that maintains UPF when wet, plus a chin cord. Straw is a poor choice here.

Frequently asked questions

For specific picks vetted against these criteria, see our guide to the best sun hats for hiking. Browse all hike guides or read how we research and rate gear.