UV Index Lookup by City and State

Find the average UV index for your area, see monthly UV trends, and get personalized sun protection recommendations. Select your state and city below to see detailed UV data. For today's live UV forecast, check the EPA UV Index API with your zip code.

Look Up Your UV Index

UV Index by State

Browse UV index data for every US state. Click a state to see city-level UV data, monthly trends, and sun safety information.

AL 5.8 High AK 2 Low AZ 7.5 Very High AR 5.5 High CA 6.8 High CO 6.5 High CT 4 Moderate DE 4.6 Moderate DC 4.8 Moderate FL 7.2 Very High GA 5.9 High HI 9.2 Very High ID 4.8 Moderate IL 4.3 Moderate IN 4.4 Moderate IA 4.2 Moderate KS 5.4 High KY 4.8 Moderate LA 6.3 High ME 3.5 Moderate MD 4.7 Moderate MA 3.9 Moderate MI 3.8 Moderate MN 3.6 Moderate MS 6 High MO 4.9 Moderate MT 4.2 Moderate NE 4.6 Moderate NV 7 High NH 3.6 Moderate NJ 4.4 Moderate NM 7.3 Very High NY 4 Moderate NC 5.3 High ND 3.8 Moderate OH 4.1 Moderate OK 5.8 High OR 3.8 Moderate PA 4.1 Moderate RI 4 Moderate SC 5.9 High SD 4.3 Moderate TN 5.2 High TX 6.8 High UT 6.5 High VT 3.5 Moderate VA 4.9 Moderate WA 3.5 Moderate WV 4.4 Moderate WI 3.7 Moderate WY 5.2 High

Understanding the UV Index

The UV Index is a measure of the strength of ultraviolet radiation from the sun at a particular place and time. Developed by the World Health Organization, it ranges from 0 (nighttime) to 11+ (extreme tropical midday sun). The index is a key tool for understanding your risk of sunburn, skin damage, and long-term skin cancer risk from sun exposure.

UV radiation is influenced by several factors: latitude (closer to the equator means stronger UV), altitude (UV increases about 10-12% per 1,000 meters of elevation), time of year (summer solstice peaks), cloud cover, ozone layer thickness, and surface reflection (snow, sand, and water reflect UV and increase your effective exposure). Cities at high altitude, like Denver and Santa Fe, experience significantly higher UV than cities at the same latitude near sea level.

UV Index Scale

UV Index Level Sunburn Risk Protection Needed
0-2 Low Minimal for most people Sunglasses; SPF 15 if sensitive
3-5 Moderate Fair skin burns in 30-45 min SPF 30, hat, sunglasses, seek shade at midday
6-7 High Fair skin burns in 15-25 min SPF 30+, protective clothing, limit midday sun
8-10 Very High Fair skin burns in 10-15 min SPF 50+, full protection, avoid midday sun
11+ Extreme Fair skin burns in under 10 min SPF 50+, stay indoors 10 AM-4 PM if possible

Sunburn Time by Skin Type

How quickly you burn depends on both the UV index and your skin type. The Fitzpatrick scale classifies skin into six types based on response to UV exposure. Below are approximate minutes to first redness (minimal erythemal dose) at various UV levels without sunscreen.

Skin Type Description UV 3 UV 6 UV 9 UV 12
Type I Very Fair - Always burns, never tans. Pale white skin, freckles, red/blonde hair. 22 min 11 min 7 min 6 min
Type II Fair - Burns easily, tans minimally. White skin, blonde/light brown hair. 33 min 17 min 11 min 8 min
Type III Medium - Burns moderately, tans gradually. Cream white to light brown skin. 67 min 33 min 22 min 17 min
Type IV Olive - Burns minimally, tans easily. Light brown to olive skin. 100 min 50 min 33 min 25 min
Type V Brown - Rarely burns, tans profusely. Brown skin. 133 min 67 min 44 min 33 min
Type VI Dark Brown/Black - Almost never burns. Dark brown to black skin. 167 min 83 min 56 min 42 min

Frequently Asked Questions

What UV index level is dangerous?

Any UV index above 3 carries a meaningful risk of skin damage for fair-skinned individuals. At UV 6-7 (High), unprotected fair skin can burn in 15-25 minutes. At UV 8-10 (Very High), burns can occur in as little as 10 minutes. UV 11+ (Extreme), common in desert and tropical locations during summer, can cause burns in under 10 minutes for fair skin. Darker skin types have more natural protection but are still at risk for UV damage, especially eye damage, at high UV levels. Everyone should take precautions when the UV index exceeds 3.

Does cloud cover reduce the UV index?

Thin or scattered clouds block very little UV radiation — you can still receive 80% or more of UV exposure on a partly cloudy day. Thick, dark overcast conditions reduce UV significantly but never eliminate it entirely. Fog and haze have minimal effect on UV. The most common sunburn scenario is a partly cloudy day when people feel cooler and skip sun protection, not realizing they are still receiving strong UV exposure. Always check the UV index forecast rather than relying on how sunny it looks.

How does altitude affect the UV index?

UV radiation increases approximately 10-12% for every 1,000 meters (3,280 feet) of elevation gain. This means a city like Denver (5,280 feet / 1,609 meters) experiences roughly 16% more UV than a sea-level city at the same latitude, and mountain towns like Aspen or Park City even more. High-altitude locations also tend to have cleaner, thinner air with less atmospheric scattering, further increasing UV intensity. If you live at or travel to high elevation, you need stronger sun protection than the latitude alone would suggest.

When is the UV index highest during the day?

The UV index follows a predictable daily curve, rising after sunrise, peaking around solar noon (approximately 1:00 PM during daylight saving time), and declining through the afternoon. About 60% of the day's total UV radiation arrives between 10 AM and 2 PM, and roughly 80% between 9 AM and 3 PM. The peak midday UV can be 2-3 times higher than the morning or late afternoon values. Planning outdoor activities for early morning or late afternoon significantly reduces your UV exposure.

Can I get sunburned in winter?

Yes, although winter UV levels are lower in most of the US, several factors can still cause burns. Snow reflects up to 80% of UV radiation, effectively doubling your exposure on sunny winter days — this is why skiers frequently get sunburned. High-altitude winter activities combine the altitude UV boost with snow reflection. In southern states like Florida, Arizona, and Texas, winter UV levels of 4-6 are common and still require sun protection. The UV index data on this site shows monthly averages to help you plan year-round.

How often should I reapply sunscreen?

Reapply sunscreen every 2 hours, or immediately after swimming, sweating heavily, or towel drying. Most people apply only 25-50% of the recommended amount, so the effective SPF is much lower than labeled. Use a full ounce (shot glass) of sunscreen for full body coverage. For very high and extreme UV (8+), consider reapplying every 60-90 minutes. Sunscreen degrades in sunlight over time regardless of activity, so the 2-hour rule applies even if you are sitting still in the shade.