Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Neiafu, Tonga, where the tropical climate can lead to high levels of UV radiation, especially during midday hours. Being aware of the UV levels not only helps prevent painful sunburn but also plays a key role in maintaining long-term skin health. With a typical peak reaching 8 around noon, the sun's intensity can pose significant risks if adequate precautions aren't taken. Whether you’re enjoying the beautiful beaches or engaging in outdoor activities, keeping an eye on the UV Index will help ensure you stay safe while soaking up the island sun.
The UV Index shows a striking rise in intensity as the day progresses. Starting from a minimal level of 0 at 7:00 AM, it gradually peaks at 8 between noon and 1 PM. This marks the sun's most powerful impact, urging caution for outdoor activities. After this zenith, the index begins to decline, dropping to 5 by 3 PM, before further easing to 1 as evening approaches. With values fluctuating from 0 to 8, the day underscores the importance of sun protection, especially during those midday hours when the UV rays are at their most potent.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 0 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 2 | low | 45 min |
| 10:00 | 4 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 8 | very high | 15 min |
| 13:00 | 8 | very high | 15 min |
| 14:00 | 7 | high | 25 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 data reveals notable seasonal changes in ultraviolet radiation, with January through April consistently marked by extreme levels (UV Index 16 to 12), leading to a dangerously short burn time of just 10 minutes. This continues until May, when the index drops slightly to 9, categorized as very high, allowing for a marginally longer exposure time of 15 minutes. The high-risk months to be especially cautious are from February to April and again in August to November, as these months exhibit extreme UV ratings. As summer approaches in June and July, while the UV Index decreases to 7 and 8 respectively, residents and visitors should remain vigilant during July, classified as very high. In contrast, October and November return to extreme levels (UV Index 14 and 15), indicating that sun safety remains crucial even in the fall. For everyone’s safety, it is advisable to wear protective clothing, apply sunscreen, and limit sun exposure during peak hours, particularly in the high-risk months.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tatakamotonga UVI | 16 | 15 | 14 | 11 | 9 | 7 | 8 | 10 | 11 | 13 | 15 | 16 |
| Haveluloto UVI | 16 | 15 | 14 | 11 | 9 | 7 | 8 | 10 | 11 | 13 | 15 | 16 |
| Lapaha UVI | 16 | 15 | 14 | 11 | 9 | 7 | 8 | 10 | 11 | 13 | 15 | 16 |
| Nuku'alofa UVI | 16 | 15 | 14 | 11 | 9 | 7 | 8 | 10 | 11 | 13 | 15 | 16 |
| Neiafu | 16 | 16 | 15 | 12 | 9 | 7 | 8 | 11 | 12 | 14 | 15 | 16 |