UV Index in Norwalk, United States

Last updated: June 2, 2025

In Norwalk, United States, understanding the UV Index is crucial for protecting your skin and overall health. With maximum UV levels peaking at 11 during midday, awareness of these levels can significantly reduce the risk of sunburn and long-term skin damage. The local Csb climate offers a mix of sunny and overcast days, but when the sun is shining, the risk for overexposure rises sharply. By keeping an eye on the UV Index, residents can take proactive measures to enjoy the beautiful weather while safeguarding their skin from harmful rays.

Hourly UV Index in Norwalk

The UV Index throughout the day follows a dynamic trajectory, peaking during midday hours. Early in the morning, at 7:00 AM, the index is a mere 1, indicating minimal risk. However, as the sun rises, the intensity escalates sharply, reaching 11 by 12:00 PM and 1:00 PM, signaling a high risk period for unprotected skin. By 3:00 PM, there's a noticeable decline to 8, and it continues to fall gently, arriving back at 1 by 7:00 PM. It’s crucial to stay protected during those peak hours, especially between 10:00 AM and 3:00 PM, when the sun's rays are the strongest.

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	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in Norwalk

Throughout the year, UV Index levels fluctuate significantly, reflecting seasonal changes in sun exposure. January and December exhibit moderate UV levels (Index 4), with a burn time of 30 minutes. As spring arrives, February escalates to a high UV Index of 6 with a reduced burn time of 25 minutes. The risk peaks in March and April, hitting a very high UV Index of 8 and 10 respectively, with critical burn times of just 15 minutes. The summer months of June and July show the highest UV Index at 11, categorized as extreme, where even a brief 10-minute exposure can lead to burns. Although August and September remain very high, it’s crucial to remain vigilant. As UV levels taper off in October and November, a moderate level of risk is present again. Residents and visitors are advised to protect themselves with sunscreen, hats, and sunglasses, especially from March to September when UV exposure can be particularly harmful.

Monthly Maximum UV Index for Norwalk, United States

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

The table above highlights how UV exposure in Norwalk 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.

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