UV Index in London, United States

Last updated: May 3, 2025

Understanding the UV Index is crucial for residents and visitors in London, United States, where sun exposure can pose significant risks to skin health. Awareness of UV levels helps in preventing sunburns and long-term skin damage, particularly during peak daylight hours. With a Cfa climate characterized by warm summers, London experiences elevated UV exposure, especially around midday when the index can soar to levels as high as 11. By staying informed about the UV Index, you can enjoy the outdoors safely while protecting your skin from harmful rays.

Hourly UV Index in London

As the sun rises on this vibrant day, the UV Index begins its steady ascent. Starting at a mild 1 at 07:00, it quickly climbs to 3 by 09:00, signaling that it’s time to enjoy some outdoor activities with caution. By 10:00, the index reaches a moderate 5, but the real heat kicks in at 11:00, peaking at an intense 11 from 13:00 to 14:00. During this peak, sun protection is crucial, especially for those planning to be outdoors. As the afternoon progresses, the UV Index gently declines, dropping to 7 by 16:00 and tapering off to 4 by 17:00. As the sun sets, the index returns to 1 by 19:00, marking a gentle end to a day of vibrant sunlight.

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	11	extreme	10 min
14:00	11	extreme	10 min
15:00	9	very high	15 min
16:00	7	high	25 min
17:00	4	moderate	30 min
18:00	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in London

Throughout the year, UV Index levels fluctuate significantly, with higher risks typically observed from March to August. The high-risk months are especially highlighted in April, May, June, July, and August, where the UV Index reaches extreme levels of 11 and the recommended burn times drop to just 10 minutes. Visitors and residents are strongly advised to take protective measures during these months, such as wearing sunscreen, protective clothing, and seeking shade, particularly during midday hours. As the year progresses towards the fall and winter months, UV exposure decreases, making January and December months of moderate risk, where burn times are longer at 30 minutes. Staying informed about daily UV levels can help ensure safety while enjoying outdoor activities.

Monthly Maximum UV Index for London, United States

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

The table above highlights how UV exposure in London 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.

London'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
London	3	6	7	9	11	11	11	10	9	7	5	3
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