UV Index in Phoenix, United States

Last updated: July 2, 2025

In Phoenix, Arizona, awareness of the UV Index is crucial for protecting your skin from harmful ultraviolet radiation. With the sun's intensity peaking around midday—reaching daily highs of 10—understanding UV levels can significantly aid in sunburn prevention and maintaining long-term skin health. Given Phoenix's arid climate and abundant sunshine, residents and visitors alike face heightened risks during summer months and sunny days. By staying informed about the UV Index, you can enjoy the outdoors safely while minimizing the potential for skin damage.

Hourly UV Index in Phoenix

The UV Index reveals a dynamic ascent and descent throughout the day, peaking with intensity during midday. Starting at a gentle 1 at 7:00 AM, it climbs steadily, reaching 10 by 1:00 PM and maintaining this highest level until 2:00 PM. This critical window indicates significant sun exposure, and it’s essential to take precautions. As the afternoon progresses, the index begins to taper off, dropping to 8 at 3:00 PM, then gradually falling to 1 by 7:00 PM. This data highlights the importance of being sun-smart during the peak hours to minimize UV exposure risks.

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
Time	UVI	Category	Time to Burn
07:00	1	low	45 min
08:00	2	low	45 min
09:00	3	moderate	30 min
10:00	5	moderate	30 min
11:00	8	very high	15 min
12:00	9	very high	15 min
13:00	10	very high	15 min
14:00	10	very high	15 min
15:00	8	very high	15 min
16:00	6	high	25 min
17:00	4	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Phoenix

Throughout the year, UV index levels demonstrate significant seasonal changes, with March to September being the highest risk months for UV exposure. In particular, May and June reach an extreme UV index of 11, resulting in much shorter burn times of only 10 minutes. As summer progresses, the UV index remains quite high, reaching 10 in July and August and 8 in September. For those in the area, it is crucial to take precautions during these months—seek shade, wear protective clothing, and apply broad-spectrum sunscreen. Conversely, the UV index is at its lowest in December, indicating a low risk for sunburn, with a more extended burn time of 45 minutes. Consequently, visitors and residents should remain vigilant and adjust their sun safety practices according to the forecasted UV index throughout the year.

Monthly Maximum UV Index for Phoenix, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Phoenix. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.

Data source: Statistical UV Index data for Phoenix, based on information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

Compare Phoenix UV Index with Other United States Cities

The table above highlights how UV exposure in Phoenix compares to other major locations across United States. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.

Phoenix's solar exposure compared to other cities in United States. Generated using Copernicus Atmosphere Monitoring Service information.
	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Chicago UVI	3	4	6	8	9	10	10	9	8	6	4	2
Brooklyn UVI	3	5	6	8	10	10	9	9	8	6	4	2
New York City UVI	3	5	6	8	10	10	9	9	8	6	4	2
Phoenix	3	4	7	8	11	11	10	10	8	6	4	2
Los Angeles UVI	4	6	8	9	10	11	11	10	10	7	5	4
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5