UV Index in National Park, United States

Last updated: July 2, 2025

Understanding the UV Index is crucial for anyone visiting the National Park in the United States, where the combination of a humid subtropical climate (Cfa) and high elevation can lead to intense sun exposure. With UV levels peaking at a striking 10 around midday, being aware of these levels is integral for sunburn prevention and overall skin health. As you explore the park’s stunning landscapes, knowing when to seek shade or apply sunscreen can make all the difference in enjoying your outdoor adventure safely. Stay informed about UV exposure risks throughout the day for a more enjoyable and worry-free experience!

Hourly UV Index in National Park

As the day unfolds, the UV Index experiences a dramatic rise, peaking at an intense 10 around 1 PM, signaling the highest level of harmful UV radiation. Early morning hours start gently, with a maximum of 1 at 7 AM, gradually increasing to a moderate 4 by 9 AM. The ascent continues steadily, reaching a notable 8 between 11 AM and 12 PM before soaring to its zenith. After this peak, the index begins to wane, declining to 5 by 4 PM and dropping further to a safe 1 by 7 PM. It’s vital to stay protected during the peak hours of 11 AM to 3 PM to enjoy the sunshine without compromising skin health.

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	8	very high	15 min
12:00	9	very high	15 min
13:00	10	very high	15 min
14:00	9	very high	15 min
15:00	8	very high	15 min
16:00	5	moderate	30 min
17:00	3	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in National Park

Throughout the year, the UV Index exhibits notable seasonal changes, with the highest levels occurring from April to September. During this peak period, particularly in May, June, and July, the UV Index reaches 10—categorized as very high, necessitating vigilant sun protection measures. Visitors and residents should be particularly cautious in these months, as the burn time drops to just 15 minutes. March marks the transition to high exposure, with an index of 6, while October and November see a decline to moderate levels and longer burn times of 25 to 30 minutes. To safeguard against UV-related health risks, it is essential to wear sunscreen, hats, and protective clothing, especially during the high-risk months of April to September.

Monthly Maximum UV Index for National Park, United States

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

The table above highlights how UV exposure in National Park 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.

National Park'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
National Park	3	5	6	9	10	10	10	9	8	6	4	3
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