UV Index in Janesville, United States

Last updated: May 3, 2025

Understanding the UV Index is essential for residents of Janesville, United States, as it serves as a crucial tool for protecting skin health and preventing sunburn. With a climate classified as Dfa, Janesville experiences significant sun exposure, especially during peak hours when the UV Index can soar to 9. By being aware of daily UV levels, you can make informed decisions about sun protection, ensuring your outdoor activities remain safe and enjoyable. Whether you're lounging at a park or simply running errands, keeping an eye on the UV Index helps you minimize the risks associated with harmful UV radiation.

Hourly UV Index in Janesville

At 07:00, the UV Index begins at a mild 1, perfect for a leisurely morning stroll. As the sun rises higher, it gradually climbs to 2 by 08:00 and reaches 3 at 09:00. The intensity really kicks in at 10:00, jumping to 5, and soars to its peak of 9 by 13:00. This high exposure continues through 14:00, making midday the most crucial time for sun protection. As the afternoon wanes, the index dips to 7 at 15:00, then continues to decline to 5 at 16:00 and settles back to 3 by 17:00. The evening brings relief with a return to 2 by 18:00 and finally drops to 1 at 19:00. Make sure to stay protected during those peak hours!

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	7	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	7	high	25 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 Janesville

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 Janesville, United States

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

The table above highlights how UV exposure in Janesville 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.

Janesville'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
Janesville	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