UV Index in London, United States

Last updated: May 3, 2025

In London, United States, being aware of the UV Index is crucial for safeguarding your skin and overall health. Understanding UV levels can significantly reduce the risk of sunburn and long-term skin damage, promoting healthier outdoor activities for residents and visitors alike. Given London’s humid subtropical climate (Cfa), the sun can be particularly intense during midday hours, with UV Index levels peaking at a high of 11. By staying informed about daily UV exposure, you can enjoy the sunshine responsibly and protect yourself from its harmful effects.

Hourly UV Index in London

The UV Index throughout the day presents a clear trajectory of increasing intensity, peaking dramatically as the sun reaches its zenith. At 07:00, the index starts modestly at 1, signifying minimal risk. However, as the hours roll on, from 08:00 to 10:00, it climbs steadily to 6, marking the onset of moderate exposure. The real surge occurs between 11:00 and 13:00, where the index hits a staggering 11, indicating a very high risk for unprotected skin. Even as it begins to taper off in the afternoon—returning to 9 by 15:00 and further down to 4 by 17:00—the day's UV intensity serves as a reminder of the importance of sun protection. By 19:00, it drops back to a safe 1, allowing for a sigh of relief as daylight wanes. Embrace the sun wisely!

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	6	high	25 min
11:00	8	very high	15 min
12:00	10	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	6	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

The UV Index experiences significant seasonal changes, peaking during the summer months. From January to April, the index rises from a moderate level of 4 to a very high 10, indicating increased risk for skin damage. The high-risk months are March through August, where the UV Index reaches extraordinary heights of 10 and 11, with burn times drastically reducing to as little as 10 minutes. It is crucial for visitors and residents to take protective measures, such as wearing sunscreen, sunglasses, and protective clothing, especially during these peak months when exposure can be extremely harmful. As the year progresses into fall, the UV Index decreases but remains significant through October, making sun safety a year-round consideration.

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
Los Angeles UVI	4	6	8	9	10	11	11	10	10	7	5	4
London	4	6	8	10	10	11	11	10	9	7	5	4
Houston UVI	5	8	9	11	11	12	12	11	10	9	7	5