Last updated: June 2, 2025
In Longwood, part of the remote Saint Helena, Ascension and Tristan da Cunha archipelago, understanding the UV Index is crucial for maintaining skin health and preventing sunburn. The UV Index serves as a daily reminder to protect yourself from harmful ultraviolet rays, especially during peak exposure hours when levels soar—reaching a maximum of 8 around midday. With a BWh climate featuring warm temperatures and intense sunlight, residents and visitors alike should be aware of UV risks throughout the day. Staying informed about these levels not only fosters better skin care practices but also enhances overall well-being in this stunning yet sun-drenched locale.
As the day breaks, the UV Index gradually rises, peaking at a robust 8 at 12:00 PM, signaling the sun's intensity is at its highest. Starting from a mild 1 at 07:00 AM and 08:00 AM, the UV levels steadily climb, hitting 5 by 10:00 AM. By 11:00 AM, a brisk 7 indicates that sun safety measures are essential. The intensity slightly declines after noon, tapering off to 6 at 2:00 PM, and then gradually decreases to a 4 by 3:00 PM. By evening, the UV Index drops back to a mere 1 at 5:00 PM and ultimately falls to 0 after 6:00 PM, signaling a safe return home as the sun sets. Keep this UV pattern in mind for outdoor activities to protect your skin and enjoy the day!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 7 | high | 25 min |
| 14:00 | 6 | high | 25 min |
| 15:00 | 4 | moderate | 30 min |
| 16:00 | 2 | low | 45 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 0 | low | 45 min |
| 19:00 | 0 | low | 45 min |
Throughout the year, UV Index levels display significant seasonal variations, with extreme levels persisting from January to April and again in September to November. The highest UV Index is recorded in the first four months of the year, peaking at 15, necessitating a cautious approach with a burn time of only 10 minutes. As temperatures rise, the UV Index decreases slightly in May and June, yet still maintains a very high category, allowing for a burn time of 15 minutes. The late summer months, particularly August, report slightly elevated levels before dropping again in the fall. Visitors and residents should take special care during high-risk months, particularly from January to April and September to November, by using appropriate sun protection strategies such as sunscreen, wearing protective clothing, and seeking shade during peak hours to minimize sun exposure and risk of skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Edinburgh of the Seven Seas UVI | 14 | 13 | 11 | 7 | 4 | 3 | 3 | 5 | 8 | 10 | 12 | 15 |
| Longwood | 15 | 15 | 13 | 12 | 9 | 8 | 8 | 10 | 11 | 14 | 14 | 15 |
| Jamestown UVI | 15 | 15 | 13 | 12 | 9 | 8 | 8 | 10 | 11 | 14 | 14 | 15 |
| Half Tree Hollow UVI | 15 | 15 | 13 | 12 | 9 | 8 | 8 | 10 | 11 | 14 | 14 | 15 |
| Georgetown UVI | 14 | 14 | 14 | 13 | 12 | 10 | 10 | 11 | 12 | 13 | 14 | 14 |