uv is backed by Astral, the creators of Ruff. Install uv with our official standalone installer: Then, check out the first steps or read on for a brief overview. uv may also be installed with pip, Homebrew, and more. See all of the methods on the installation page. UV radiation is present in sunlight and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs, Cherenkov radiation, and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. Detailed UV forecast charts, with today's UV radiation in real-time. Check the accurate UV index today and hourly UV forecast for your location. Protect your skin with real-time, local ultraviolet radiation tracking. Get the Current UV Index and 5 day Hourly UV Index Forecast for 56 Cities in San Diego County, CA. UV index forecast for San Diego, California with an hourly NOAA outlook, six-day forecast, protection window, exposure estimate, temperature, and air quality. Live UV index for your exact location, time-to-sunburn for your skin type, today's peak, and when you actually need sunscreen. Free, instant, no app. On this page, you can find the current UV Index and hourly 5 day UV Index forecast for San Diego, San Diego County, California (CA). The Ultraviolet Index forecast, which measures the radiation from the sun that reaches the Earth's surface is updated daily. Detailed hour-by-hour UV index forecast for San Diego — today and tomorrow. Includes UV level, clear-sky UV, weather conditions, and temperature for each hour. Live UV index across 200+ cities worldwide, as of 20:25 (UTC). Track the UV index right now, the hourly UV forecast, daily peak times, and sun protection advice for cities worldwide — free, fast, and private. No sign-up, no tracking.