UV Index

The UV Index is the forecast measure of ultraviolet radiation from the sun at a boat’s location and time, typically expressed on a scale from low to extreme. In a marine context it indicates how quickly crew on deck can be sunburnt or suffer eye and skin damage, with exposure intensified by reflection from the sea, white decks, sails and spray.

For boaters, a high UV Index affects watchkeeping, cockpit comfort and fatigue management on coastal hops and offshore passages. It should be considered alongside Sunny conditions, Cloud Cover and Temperature, because strong UV can occur even when breeze or partial cloud makes conditions feel cool. Plan shade, hats, sunglasses, sunscreen and hydration before long helm or foredeck work.

In PredictWind forecasts, UV risk is best assessed with the broader weather picture: cloud, rain, air temperature and timing of daylight hours. For multi-day passages, checking forecasts before departure and updating via the Offshore App helps crews schedule exposed jobs and rest periods more safely.