UV Index in Fort Defiance, United States

Last updated: July 2, 2025

In Fort Defiance, United States, understanding the UV Index is crucial for protecting your skin and overall health. With maximum values soaring to a staggering 13 during the peak afternoon hours, awareness of UV levels can help prevent painful sunburns and long-term skin damage. Nestled in a BSk climate zone, Fort Defiance often faces intense sun exposure, making it vital for residents and visitors alike to stay informed. By keeping an eye on the UV Index, you can enjoy the beautiful outdoors while minimizing your risk of harmful effects from the sun's rays.

Hourly UV Index in Fort Defiance

Experience the dynamic rise and fall of the UV Index throughout the day, peaking at 1 PM with a striking 13—the highest level of the day. As the sun climbs higher, the index escalates from a gentle 1 at 7 AM to a brilliant 11 by noon, urging outdoor enthusiasts to take precautions. By 11 AM, a 9 signals moderate risk, prompting sun safety awareness. The decline starts after 2 PM, dropping to 7 by 4 PM and sinking back to 1 by 7 PM as twilight approaches. This hourly pattern highlights the importance of sun protection during the midday hours, especially when the UV index peaks!

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	4	moderate	30 min
10:00	6	high	25 min
11:00	9	very high	15 min
12:00	11	extreme	10 min
13:00	13	extreme	10 min
14:00	12	extreme	10 min
15:00	10	very high	15 min
16:00	7	high	25 min
17:00	5	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Fort Defiance

Throughout the year, UV Index levels fluctuate, indicating varying risks for skin exposure. The high-risk months are primarily from March to September, where the UV Index peaks at 13 in both June and July, classified as extreme, resulting in a burn time of only 10 minutes. Visitors and residents should prioritize skin protection during these months with appropriate sunscreen, protective clothing, and seeking shade during peak hours. The months of February and October also present very high UV levels of 8, with shorter burn times of 15 minutes, necessitating caution. Conversely, January, November, and December feature moderate to high UV levels, with more forgiving burn times, though protective measures should still be considered. Emphasizing sun safety year-round is essential for both health and well-being.

Monthly Maximum UV Index for Fort Defiance, United States

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Fort Defiance. 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 Fort Defiance, 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 Fort Defiance UV Index with Other United States Cities

The table above highlights how UV exposure in Fort Defiance 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.

Fort Defiance'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
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
Fort Defiance	5	8	9	11	12	13	13	12	11	8	6	4