UV Index
UV Index
Today's UV index in Flagstaff, United States 
will be up to 11.2, indicating a extreme level of sun exposure for the average person. Check our tips for today to make sure you're safe in the sun.
Last checked: 2025-05-09
UV index at 11.2 in Flagstaff means extreme risk: limit outdoor time especially from 10 a.m. to 4 p.m., actively seek shade, wear protective clothing, broad-brimmed hat, apply SPF 30+ sunscreen every 2 hours, and wear UV-blocking sunglasses. Watch for bright surfaces like water and snow increasing UV exposure.
The UV index in Flagstaff is moderate to high during summer months, often ranging between 5 and 8, but it tends to be lower in winter, around 1 to 3. Seasonal patterns in Flagstaff show cold snowy winters with temperatures often below freezing, mild springs, warm summers with occasional thunderstorms, and cool, dry autumns. Compared to the wider region, Flagstaff is cooler and wetter than much of Arizona, which is mostly desert, and its higher elevation gives it more snow than neighboring states like New Mexico and Nevada.
See the UV index hour by hour for Flagstaff, along with the temperature and how cloudy it is. If the UV level is higher than moderate, it's best to avoid direct sunlight.