UV Index in Half Tree Hollow, Saint Helena, Ascension and Tristan da Cunha

Last updated: July 2, 2025

Understanding the UV Index in Half Tree Hollow is essential for maintaining skin health and preventing sunburn, especially in this BWh climate where typical UV exposure can be a concern. During the sunniest hours—particularly between 11:00 AM and 1:00 PM—the UV Index can reach a maximum of 8, indicating a very high risk of harm from unprotected sun exposure. Being aware of these levels helps residents and visitors take proactive steps to protect their skin and enjoy the outdoors safely. Whether you're hiking, exploring, or simply relaxing in the sun, staying informed about UV levels is crucial for safeguarding your health in this beautiful region.

Hourly UV Index in Half Tree Hollow

At dawn, the UV Index remains low, peaking at 1 by 08:00. As the sun rises higher, a notable increase occurs, reaching 3 at 09:00 and escalating dramatically to a maximum of 8 from 12:00 to 13:00. This midday surge indicates a higher risk for sun exposure, making it essential to take precautions such as wearing sunscreen and protective clothing. The intensity then gradually declines, dropping to 4 by 15:00, and continuing its descent to 0 by 19:00, marking the end of the sun’s peak influence for the day. Stay mindful of these hourly fluctuations to enjoy the sun safely!

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
TimeUVICategoryTime to Burn
07:001low45 min
08:001low45 min
09:003moderate30 min
10:005moderate30 min
11:007high25 min
12:008very high15 min
13:008very high15 min
14:006high25 min
15:004moderate30 min
16:002low45 min
17:001low45 min
18:000low45 min
19:000low45 min

Monthly UV Index Trends in Half Tree Hollow

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.

Monthly Maximum UV Index for Half Tree Hollow, Saint Helena, Ascension and Tristan da Cunha

The monthly maximum UV Index (UVI) represents the highest UV radiation level recorded each month in Half Tree Hollow. It measures the strength of ultraviolet radiation from the sun and helps assess the risk of sunburn and UV-related health issues.
JanFebMarAprMayJunJulAugSepOctNovDec151513129881011141415
Data source: Statistical UV Index data for Half Tree Hollow, based on information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

Compare Half Tree Hollow UV Index with Other Saint Helena, Ascension and Tristan da Cunha Cities

The table above highlights how UV exposure in Half Tree Hollow compares to other major locations across Saint Helena, Ascension and Tristan da Cunha. This comparison helps travelers and residents better understand regional sun intensity and plan outdoor activities with sun safety in mind.
Half Tree Hollow's solar exposure compared to other cities in Saint Helena, Ascension and Tristan da Cunha. Generated using Copernicus Atmosphere Monitoring Service information.
 JanFebMarAprMayJunJulAugSepOctNovDec
Edinburgh of the Seven Seas UVI141311743358101215
Half Tree Hollow151513129881011141415
Jamestown UVI151513129881011141415
Longwood UVI151513129881011141415
Georgetown UVI141414131210101112131414