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Live forecasts update automatically; written guidance last reviewed 13 June 2026 by the Insight Britain weather desk. Data from national met services via Open-Meteo.
Live data from Open-Meteo · updates automatically ·
The UV index measures the strength of ultraviolet radiation from the sun, using a scale from 0 to 11+ to indicate the risk of harm from unprotected sun exposure. For today’s specific levels across the UK, refer to the live forecast above.
What is the UV index and how is it measured?
The UV index is an international standard developed by the World Health Organization. It quantifies the level of solar UV radiation reaching the Earth’s surface at a given time and location. The scale ranges from 0 (Low) to 11+ (Extreme), with each category assigned a colour band: Low (green), Moderate (yellow), High (orange), Very High (red), and Extreme (purple). The higher the number, the greater the potential for skin and eye damage if you stay outside without protection. You can often see the uv index weather forecast alongside temperature and wind, including the uv index met office data used in many official apps.
When is the UV index highest in the UK?
UV levels in the UK are highest between May and August, especially around midday (11am–3pm) when the sun is at its zenith. Even on a cool day, the uv index can be strong enough to cause sunburn within 20–30 minutes during summer months. The highest uv index in the UK typically occurs in July, but the exact daily figure depends on cloud cover, altitude, and latitude. Check the live conditions above for your location.
Can you get sunburn on cloudy or cool days?
Yes. Up to 80% of UV radiation can pass through light cloud cover, and UV is not related to temperature – you can burn even when it feels cool. Snow, sand, and water also reflect UV, increasing exposure. Always check the uv index today uk in the live forecast above rather than relying on how warm it feels. For example, uv index today london might show a Moderate level even on a cloudy spring afternoon, so sunscreen remains advisable.
How to stay safe when the UV index is high
When the UV index reaches 3 (Moderate) or above, the NHS advises using SPF 30+ sunscreen, wearing a hat and UV-protective sunglasses, and seeking shade between 11am and 3pm. Avoid sunbeds and do not let children burn. For extended outdoor activity, reapply sunscreen every two hours. For more summer weather advice, see our UK Heatwave & Hot Weather guide. You can also check the 10-day forecast to plan your sun protection days ahead.
Frequently Asked Questions
What is the UV index today in London?
The uv index today london varies with weather conditions. For the most current reading, refer to the live forecast above. As a general guide, London’s summer UV index often reaches High (6–7) on clear afternoons, while in winter it usually stays Low. Always check live data for the exact value.
Is the UV index the same as the Met Office forecast?
The uv index met office forecast uses the same standardised scale as other official weather services. Many apps and websites source their UV data from the Met Office. The live conditions above are updated regularly to give you the most accurate reading for your chosen location.
What is the UK UV index by month?
The uk uv index by month peaks in June and July (often High or Very High in southern parts). May and August are typically Moderate to High. From November to February, UV levels are almost always Low. March and April rise to Moderate, while September and October fall back to Moderate then Low. The live forecast above shows today’s specific level.
For more weather insights and official measurement standards, visit our UK weather hub and our Sources & Standards page. If you are planning outdoor activities, also check today’s warmest place in the UK.