How to monitor UV radiation levels, sun arcs, and WeatherKit precipitation forecasts from your wrist.
By Space Editorial Team • 2026-07-10 • 4 min read
Solar Protection & Precipitation Monitoring
Weather conditions shift rapidly during outdoor activities. Reading solar radiation (UV index) and localized rain forecasts directly from your watch face helps you prepare without pulling out your phone.
Understanding the Global Solar UV Index
The World Health Organization (WHO) solar UV scale measures ultraviolet radiation:
0 to 2 (Low): Safe for extended exposure without special protection.
3 to 5 (Moderate): Sunscreen (SPF 30+) recommended; seek shade near solar noon.
6 to 7 (High): Protection required; wear hats and sunglasses.
8 to 10+ (Very High / Extreme): Avoid direct sun exposure during peak hours (11:00–15:00).
Rain Forecasts via Apple WeatherKit
Apple WeatherKit uses hyper-local radar data to deliver minute-by-minute precipitation tracking when rain is expected within the hour.
Precipitation Chance: Displays the probability of rain in your immediate area.
Precipitation Intensity: Indicates whether incoming rain is light drizzle or heavy downpour.