UV Index in Alta, United States

Last updated: August 1, 2025

Understanding the UV Index in Alta, United States is crucial for residents and visitors alike, as it can significantly impact skin health and sunburn prevention. With the city’s Dfa climate leading to varied UV exposure throughout the day, knowing when the sun's rays are most intense can help you protect yourself effectively. The UV Index peaks around midday, reaching a maximum of 10, indicating a high risk of harm from unprotected sun exposure. By staying informed about the UV levels, you can enjoy the beautiful outdoors of Alta while keeping your skin safe from damage.

Hourly UV Index in Alta

The UV index begins its ascent at 07:00, starting at a gentle 1, then climbs gradually through the morning. By 10:00, it reaches a moderate 5, but from 11:00 onwards, the sun's intensity becomes pronounced, peaking at an impressive 10 between 13:00 and 14:00. After this zenith, the index dips to 8 at 15:00 and continues its decline, settling back to 2 by 18:00. As the day winds down into the evening, the UV index drops to a low 1 by 19:00, signaling a return to safer sun exposure levels. Enjoy the sunshine while staying protected during the high points!

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	1	low	45 min
09:00	2	low	45 min
10:00	4	moderate	30 min
11:00	6	high	25 min
12:00	8	very high	15 min
13:00	9	very high	15 min
14:00	9	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 Alta

Throughout the year, the UV Index demonstrates significant seasonal fluctuations, with high-risk months typically occurring from April to September. In April, the UV Index escalates to 8, indicating very high exposure risks, and remains elevated through May (9) and June (11), where it reaches an extreme level. July (10) and August (9) continue to present very high risks, before tapering off in September (8). As a precaution, visitors and residents should take protective measures, especially during these peak months, by seeking shade, wearing protective clothing, and applying sunscreen frequently. In contrast, the UV Index drops to a moderate level (3-5) from October to March, allowing for safer outdoor activities during this period.

Monthly Maximum UV Index for Alta, United States

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

The table above highlights how UV exposure in Alta 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.

Alta'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
Alta	3	5	5	8	9	11	10	9	8	5	3	3
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