Last updated: July 2, 2025
Understanding the UV Index is essential for residents of Carletonville, South Africa, where the subtropical highland climate exposes inhabitants to varying UV levels throughout the day. Knowledge of UV levels is crucial for preventing sunburn and maintaining long-term skin health, particularly during peak hours when the UV Index reaches a maximum of 6 around noon. With Carletonville's climate presenting both sunny and overcast days, being aware of these UV exposure risks can help you enjoy the outdoors safely while protecting your skin from potential harm.
As the sun rises, the UV Index remains low, peaking only at 1 until 9:00 AM. A gradual increase sees it reach 6 by noon, indicating peak sun intensity. The high point of 6 persists until 1:00 PM, making this the ideal time to take precautions if you're outdoors. After this, the index begins to decline, dropping to 4 by 2:00 PM and falling further to 1 by 4:00 PM. By the evening, the UV levels settle at 0, ensuring a safe outdoor experience. Remember, during the midday hours, it’s crucial to stay protected under the sun!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 1 | low | 45 min |
| 09:00 | 2 | low | 45 min |
| 10:00 | 4 | moderate | 30 min |
| 11:00 | 5 | moderate | 30 min |
| 12:00 | 6 | high | 25 min |
| 13:00 | 6 | high | 25 min |
| 14:00 | 4 | 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 |
Throughout the year, UV radiation exposure exhibits significant seasonal variations, with the highest risk months peaking in January, February, and March, where the UV Index reaches an extreme level of 16 to 13, allowing for a dangerously short burn time of just 10 minutes. The trend continues into April and September, which also maintain an extreme UV Index of 11. As summer approaches, a slight decrease in UV Index is observed in May to July, with values ranging from 6 to 7, indicating a high exposure risk but allowing for longer burn times of 25 minutes. However, high caution is advised during August when the UV Index spikes back to 8 (very high). As the year closes, November and December mirror the extreme levels seen at the start of the year, necessitating constant vigilance. Therefore, visitors and residents should adopt protective measures, such as wearing sunscreen and protective clothing, especially during peak UV times, and seek shade whenever possible, particularly in the high-risk months of January through March and September through November.
UV Risk Categories
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cape Town UVI | 14 | 13 | 11 | 8 | 5 | 3 | 4 | 6 | 9 | 11 | 12 | 14 |
| Durban UVI | 14 | 13 | 12 | 9 | 6 | 4 | 5 | 7 | 9 | 11 | 13 | 15 |
| Johannesburg UVI | 15 | 15 | 13 | 10 | 7 | 6 | 6 | 8 | 11 | 12 | 14 | 16 |
| Pretoria UVI | 16 | 15 | 13 | 10 | 7 | 6 | 6 | 9 | 11 | 13 | 14 | 16 |
| Carletonville | 16 | 15 | 13 | 11 | 7 | 6 | 6 | 8 | 11 | 13 | 15 | 16 |
| Soweto UVI | 16 | 15 | 13 | 11 | 7 | 6 | 6 | 8 | 11 | 13 | 15 | 16 |