UV Index in Helena, United States

Last updated: June 2, 2025

Understanding the UV Index is essential for residents of Helena, United States, where the Cfa climate contributes to varying UV exposure throughout the day. As summer sun can escalate UV levels to 11—indicating extreme risk—being aware of these changes is crucial for sunburn prevention and maintaining skin health. With peak UV exposure typically occurring between 10 AM and 2 PM, awareness helps you better protect your skin from the harmful effects of solar radiation. Stay informed and enjoy the beautiful Helena outdoors safely!

Hourly UV Index in Helena

The UV Index for the day presents a fascinating variation as the sun climbs higher in the sky. Starting from a gentle 1 at 07:00, the intensity gradually escalates, reaching a moderate 4 by 09:00. The peak hits at 12:00 and 13:00, soaring to an intense 11, indicating a significant risk of harm from unprotected sun exposure. As the afternoon unfolds, the index begins to decline, tapering to 8 at 15:00, and by the evening, it plummets back to a 1 by 18:00. This data serves as a reminder to stay vigilant about sun safety during those peak hours when UV exposure is at its highest!

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	7	high	25 min
11:00	9	very high	15 min
12:00	11	extreme	10 min
13:00	11	extreme	10 min
14:00	10	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	1	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Helena

Throughout the year, UV levels fluctuate, with high-risk months primarily falling between February and August. Notably, April to July feature an extreme UV Index of 11 to 12, necessitating precautions to limit sun exposure to just 10 minutes during peak hours. February and March present significant risks as well, with very high UV levels of 8 and 9, leading to burn times of only 15 minutes. To safeguard your skin, residents and visitors are advised to minimize exposure during peak sun hours, wear protective clothing, and use broad-spectrum sunscreen. As the year progresses, November and December offer lower UV levels, classified as high and moderate, respectively, allowing for longer safe exposure times of 25 to 30 minutes.

Monthly Maximum UV Index for Helena, United States

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

The table above highlights how UV exposure in Helena 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.

Helena'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
Helena	5	8	9	11	11	11	12	11	10	8	6	4
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5