Last updated: July 2, 2025
Understanding the UV Index is crucial for residents of Onerahi, New Zealand, as it plays a significant role in protecting against harmful sun exposure. The UV Index provides a daily measure of solar UV radiation intensity, helping you gauge skin health risks and prevent sunburn during peak hours. With Onerahi's temperate marine climate (Cfb), UV levels can vary throughout the day, often peaking at a moderate level of 3 between 11 AM and 2 PM. Staying informed about these UV levels can empower you to enjoy the outdoors while safeguarding your skin against potential damage.
The UV Index throughout the day reveals a gradual increase in sun intensity, peaking mid-afternoon. Starting at 0 at 07:00, the index rises to 1 by 08:00 and remains moderate at 1 for the following hour. As the sun ascends, the intensity reaches 2 by 10:00, climbing further to 3 at 11:00, sustaining this level until 14:00. After this peak, a gentle decline begins, with the index dropping to 2 at 15:00, and gradually easing back to 1 by 17:00, before retreating to 0 by 18:00. For anyone spending time outdoors, the late morning to early afternoon presents the highest UV exposure; thus, caution and sun protection are highly advisable during these hours.
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 0 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 1 | low | 45 min |
| 10:00 | 2 | low | 45 min |
| 11:00 | 3 | moderate | 30 min |
| 12:00 | 3 | moderate | 30 min |
| 13:00 | 3 | moderate | 30 min |
| 14:00 | 3 | moderate | 30 min |
| 15:00 | 2 | low | 45 min |
| 16:00 | 1 | low | 45 min |
| 17:00 | 1 | low | 45 min |
| 18:00 | 0 | low | 45 min |
| 19:00 | 0 | low | 45 min |
The UV Index exhibits significant seasonal variations, with the highest levels occurring from January to March, where values reach 14 classified as extreme, necessitating a burn time of only 10 minutes. November and December also present high risks with UV Index values of 12 and 14 respectively, continuing to emphasize precautions due to the extreme exposure category. As we transition into April, the UV Index decreases to 7 (high), allowing for a longer burn time of 25 minutes, while May through July remain moderate, with UV Index values ranging from 5 to 3 and burn times averaging 30 minutes. The onset of autumn sees a return to higher readings in September (UV Index 7, high) and October (UV Index 10, very high) before diminishing later in the year. Visitors and residents should take note of high-risk months, particularly those from January to March and November to December, and should ensure adequate sun protection measures are in place to avoid harmful UV exposure.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Christchurch UVI | 13 | 12 | 9 | 6 | 3 | 2 | 2 | 3 | 5 | 9 | 10 | 12 |
| Wellington UVI | 13 | 13 | 9 | 7 | 4 | 2 | 2 | 4 | 6 | 9 | 10 | 13 |
| Hamilton UVI | 14 | 14 | 10 | 7 | 4 | 3 | 3 | 5 | 7 | 10 | 11 | 13 |
| Manukau City UVI | 14 | 14 | 10 | 7 | 4 | 3 | 3 | 5 | 7 | 10 | 11 | 13 |
| Auckland UVI | 14 | 14 | 10 | 7 | 4 | 3 | 3 | 5 | 7 | 10 | 11 | 13 |
| Onerahi | 14 | 14 | 11 | 7 | 5 | 3 | 3 | 5 | 7 | 10 | 12 | 14 |