Last updated: July 2, 2025
Understanding the UV Index is crucial for residents and visitors in Kolonga, Tonga, where the sun shines intensely due to its tropical Af climate. Being aware of UV levels can help prevent sunburn and protect your skin health, especially during peak hours when the UV Index reaches significant levels of 6 to 8 between 11:00 AM and 1:00 PM. With such values indicating a higher risk of harm from unprotected sun exposure, knowing when to seek shade or apply sunscreen can make a significant difference in safeguarding your skin against the sun’s harmful rays. Stay informed and enjoy the beautiful Tongan scenery while prioritizing your health!
As the day unfolds, the UV Index paints a vivid picture of sun exposure. At 07:00, the sun is just waking up with a UV Index of 0, then steadily rises to 1 by 08:00. By 09:00, it nudges up to 2, before hitting a moderate 4 at 10:00. The intensity peaks at 12:00 and 13:00, reaching a notable 8, indicating a time when protective measures are crucial. As the afternoon rolls on, the index begins to descend, dropping to 7 at 14:00, then falling further to 5 by 15:00. The sun's strength wanes into the evening, landing at 2 by 16:00, and tapering off to 1 by 17:00 and 18:00. Finally, by 19:00, the index returns to 0, as the sun sets, marking the end of the high UV exposure day. Remember to protect your skin during those peak hours!
| 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 | 6 | 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 | 2 | low | 45 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 1 | low | 45 min |
| 19:00 | 0 | low | 45 min |
The UV Index experiences significant seasonal variation, with the highest levels occurring from January to April, where the index reaches extreme levels (15-16) and a burn time of only 10 minutes. November and December also present extreme UV conditions. May marks a transition to very high levels (UV Index 9), with a burn time extending to 15 minutes, while June to August see a decrease in UV intensity yet maintain very high levels, particularly in July and August. As September through October approach extreme levels again, it’s crucial for residents and visitors to take precautions year-round. Sunscreen, protective clothing, and limited sun exposure during peak hours (10 AM to 4 PM) are highly advised, especially during the high-risk months of January to April and September to November.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Kolonga | 16 | 15 | 14 | 11 | 9 | 7 | 8 | 10 | 11 | 13 | 15 | 16 |
| 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 UVI | 16 | 16 | 15 | 12 | 9 | 7 | 8 | 11 | 12 | 14 | 15 | 16 |