UV Index in Phoenix, Arizona Today

What the UV index means in Phoenix

The UV index is a simple 0 to 11+ scale for the strength of the sun's ultraviolet radiation. The higher the number, the faster unprotected skin can burn. In Phoenix, like everywhere, the reading rises and falls through the day and shifts with the seasons, cloud cover, and how high the sun sits in the sky.

Use the live reading at the top of this page to decide what you need right now. As a rule of thumb: at UV 3 or above, wear sunscreen and a hat; at UV 6 and above, add shade during the middle of the day; at UV 8 and above, treat midday sun with real caution.

UV in Phoenix: geography and seasons

At 33.5° N, Phoenix sits in the subtropics. UV is strong for much of the year and peaks around June and July, when the sun climbs almost directly overhead at midday. At about 331 m (1,086 ft) of elevation, altitude adds a little to Phoenix's UV, which climbs around 10% per 1,000 m of height.

Sources: coordinates and elevation from GeoNames; UV, altitude, and latitude guidance from the World Health Organization and the US EPA.

Sun-safety tips for Phoenix

• Check the current UV index above before spending time outdoors.
• Apply broad-spectrum SPF 30+ sunscreen 15 minutes before going out, and reapply every two hours.
• Seek shade between 10 a.m. and 4 p.m., when UV is strongest.
• Wear a wide-brim hat and UV-blocking sunglasses.
• Remember that UV passes through light cloud and reflects off water, sand, and snow.