UV Index in Greenwich, United States

Last updated: July 2, 2025

In Greenwich, United States, staying aware of the UV Index is crucial for safeguarding your skin and overall health. Understanding the varying UV levels throughout the day helps in preventing sunburn and reducing long-term skin damage, especially during peak hours when the index can reach as high as 10 around midday. With Greenwich’s humid continental climate, residents face unique exposure risks that may exacerbate the sun's effects. By being mindful of the UV Index, you can enjoy the outdoors while protecting your skin for years to come.

Hourly UV Index in Greenwich

The UV Index for the day showcases a striking ascent in intensity, peaking during the afternoon hours. Starting from a low of 1 at 07:00 and 08:00, the index swiftly climbs to reach 3 by 09:00. By 10:00, it escalates to a moderate 5, but the real surge occurs between 11:00 and 14:00, hitting a maximum of 10—indicating a high risk of harm from unprotected sun exposure. As the day progresses, the UV Index gradually drops, retracting to 4 by 17:00 and further declining to 1 by 19:00. It's crucial 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	1	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	4	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