UV Index in London, United States

Last updated: May 3, 2025

Understanding the UV Index is crucial for residents of London, United States, as it plays a vital role in protecting skin health and preventing sunburn. With peak UV levels reaching 10 during midday hours, awareness of these fluctuations can help you enjoy the sun safely. The climate in London, categorized as Dfa, typically results in moderate to high UV exposure, especially in the summer months. By staying informed about the UV Index, you can take proactive measures to safeguard your skin and make the most of sunny days without compromising your health.

Hourly UV Index in London

The UV Index chart reveals a dynamic daily pattern of solar intensity. Starting early in the day, the UV Index remains low, peaking at 1 by 08:00. However, as the sun reaches its zenith, the index surges dramatically—hitting 7 by 11:00 and soaring to a maximum of 10 between 13:00 and 14:00. This signals a critical window for sun exposure, where protection is essential. As the afternoon progresses, the UV levels begin to decline, dropping to 4 by 17:00, before tapering off to 1 again by evening. To stay safe, it's vital to be cautious 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	2	low	45 min
19:00	1	low	45 min

Monthly UV Index Trends in London

Throughout the year, the UV Index exhibits notable seasonal changes, with the highest levels occurring from April to September. During this peak period, particularly in May, June, and July, the UV Index reaches 10—categorized as very high, necessitating vigilant sun protection measures. Visitors and residents should be particularly cautious in these months, as the burn time drops to just 15 minutes. March marks the transition to high exposure, with an index of 6, while October and November see a decline to moderate levels and longer burn times of 25 to 30 minutes. To safeguard against UV-related health risks, it is essential to wear sunscreen, hats, and protective clothing, especially during the high-risk months of April to September.

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	5	6	9	10	10	10	9	8	6	4	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