UV Index
UV Index
Today's UV index in Jamestown, Saint Helena, Ascension and Tristan da Cunha 
will be up to 7.9, indicating a high level of sun exposure for the average person. Check our tips for today to make sure you're safe in the sun.
Last checked: 2025-05-09
With Jamestown's UV index reaching 7.9, protect your skin from harm by staying in shade, wearing protective clothing, and applying SPF 30+ sunscreen every 2 hours, especially between 10 a.m. and 4 p.m. when UV rays are strongest.
The UV index in Jamestown, Saint Helena is generally low to moderate throughout the year, rarely reaching extreme levels. Ascension Island experiences moderate to high UV levels, especially in the summer months. Tristan da Cunha has a low UV index due to its latitude and cooler climate.
Saint Helena has mild temperatures year-round with little variation between seasons, experiencing more rainfall during the winter months. Ascension sees a hot, dry season and a cooler, wetter period, with more sunshine. Tristan da Cunha is cool and windy year-round with some rainfall, showing less distinct seasonal changes.
Compared to other parts of the South Atlantic, Saint Helena and Tristan da Cunha have cooler, more temperate climates than many tropical islands. Ascension Island is hotter and drier than the others. Neighboring countries like South Africa have more extreme temperature swings and less consistent rainfall than these islands.
See the UV index hour by hour for Jamestown, along with the temperature and how cloudy it is. If the UV level is higher than moderate, it's best to avoid direct sunlight.