UV Index in Greenwich, United States

Last updated: June 2, 2025

Understanding the UV Index in Greenwich, United States, is essential for safeguarding your skin and overall health. As the sun's rays intensify, especially during the peak afternoon hours, being aware of the UV levels can help you prevent painful sunburns and long-term skin damage. With Greenwich's humid continental climate, residents and visitors often face varying exposure risks throughout the seasons. Knowing when to seek shade or apply sunscreen can make a significant difference in your sun safety routine, especially when UV levels peak at a high 10 between 1 PM and 2 PM. Stay informed and enjoy the sunshine wisely!

Hourly UV Index in Greenwich

As the sun rises, the UV Index begins its steady ascent, starting at a mild 1 at 7:00 AM. By 8:00 AM, it reaches 2, hinting at the day ahead. As we approach mid-morning, the intensity climbs to 3 by 9:00 AM and then dramatically spikes to 5 at 10:00 AM. The real peak occurs between 12:00 PM and 2:00 PM, where the index soars to a whopping 10, indicating strong sun exposure. This midday intensity begins to taper off by 3:00 PM, as it drops to 9, and continues to slide through the late afternoon, ending the day at 1 by 7:00 PM. It's crucial to stay protected during those peak hours to enjoy the sun safely!

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	9	very high	15 min
13:00	10	very high	15 min
14:00	10	very high	15 min
15:00	9	very high	15 min
16:00	7	high	25 min
17:00	5	moderate	30 min
18:00	3	moderate	30 min
19:00	1	low	45 min

Monthly UV Index Trends in Greenwich

Throughout the year, UV exposure varies significantly, peaking in the late spring and summer months. April to August represent the high-risk period, with UV Index values reaching 10; indicating a very high exposure category and a burn time as short as 15 minutes. Visitors and residents should exercise caution and take protective measures, such as wearing sunscreen and protective clothing during these months. In contrast, January and December have moderate and low UV levels, respectively, with longer burn times of 30 to 45 minutes. Action is still advisable during these months, but the intensity is notably lower, allowing for safer outdoor activities. Overall, awareness of seasonal UV changes is essential for protecting skin health year-round.

Monthly Maximum UV Index for Greenwich, United States

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

The table above highlights how UV exposure in Greenwich 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.

Greenwich'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
Greenwich	3	5	6	8	10	10	10	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