Last updated: July 2, 2025
Understanding the UV Index is crucial for anyone in Zanzibar, Tanzania, where the sun's rays can be particularly intense. With a climate characterized by warm temperatures and strong sunlight, being aware of UV levels is essential for sunburn prevention and maintaining skin health. As midday approaches, UV Index values can soar to 10, indicating a very high risk of harm from unprotected sun exposure. By learning about these levels and their implications, residents and visitors can enjoy the island’s beauty while safeguarding their skin against potential damage.
As the sun rises, the UV Index remains low at 1 from 07:00 to 09:00, ideal for early morning outdoor activities. However, as the clock strikes 10:00, it escalates dramatically to 6, urging caution for midday sun exposure. The peak intensity occurs between 12:00 and 13:00, where the UV Index soars to its maximum at 10, signaling a high risk for harm from unprotected sun exposure. As the afternoon unfolds, the index gradually declines, dropping to 8 at 14:00 and tapering down to 5 by 15:00. Finally, by 17:00, it dips back to 1, and by 19:00, it settles at 0, signaling the safe return of evening shadows. Be mindful of sun safety during those critical hours!
| 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 | 6 | high | 25 min |
| 11:00 | 9 | very high | 15 min |
| 12:00 | 10 | very high | 15 min |
| 13:00 | 10 | very high | 15 min |
| 14:00 | 8 | very high | 15 min |
| 15:00 | 5 | moderate | 30 min |
| 16:00 | 3 | moderate | 30 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
The UV Index shows a consistent pattern of extremely high levels throughout the first eight months of the year, with a notable peak from January to April, where it maintains a value of 14 and an extreme exposure category, indicating a burn time of just 10 minutes. Even in May, the UV Index remains high at 12. As we enter the summer months, June and July present a slight decrease to 10, categorized as very high, allowing for a marginally longer burn time of 15 minutes. However, August sees a return to extreme levels at 12, continuing through September, October, and November with 13. Thus, the highest-risk months for UV exposure are from January to April, as well as August to November. Visitors and residents are advised to take precautionary measures during these months, including the use of sunscreen, protective clothing, and seeking shade during peak sunlight hours to minimize the risk of skin damage.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Zanzibar | 14 | 14 | 14 | 14 | 12 | 10 | 10 | 12 | 13 | 13 | 13 | 13 |
| Dar es Salaam UVI | 14 | 14 | 15 | 14 | 12 | 10 | 10 | 12 | 13 | 13 | 13 | 13 |
| Mwanza UVI | 14 | 15 | 16 | 15 | 13 | 11 | 11 | 13 | 14 | 13 | 13 | 13 |
| Arusha UVI | 15 | 16 | 16 | 16 | 14 | 12 | 12 | 13 | 14 | 14 | 13 | 14 |
| Mbeya UVI | 16 | 16 | 16 | 16 | 13 | 11 | 11 | 13 | 14 | 14 | 14 | 15 |