Last updated: June 2, 2025
Understanding the UV Index is crucial for residents of Constantia, South Africa, as it directly impacts skin health and sunburn prevention. With the region's Mediterranean climate, characterized by warm summers and mild winters, awareness of daily UV levels is essential. During peak hours, UV levels can reach a moderate 3, indicating a need for protective measures. Knowing when to apply sunscreen and seek shade can help safeguard against harmful effects of excessive sun exposure, ensuring you enjoy the beautiful Constantia outdoors safely.
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 variation, with the highest readings occurring during the winter months and early spring. January and February remain critical months, both with an extreme UV Index of 14 and a burn time of just 10 minutes. Following closely, March also has an extreme rating of 11, emphasizing the need for protective measures. As we transition into April, the UV Index drops slightly to 8 (very high), but still requires caution, with a burn time of 15 minutes. The risk decreases during the summer months, with May to July showing moderate levels of 5 to 4, allowing for longer exposure times before burning. However, a resurgence in risk occurs in August with a high rating of 6, and September reverts to very high at 9. As the year closes, October and November return to extreme levels of 11 and 12, respectively, necessitating vigilance. Residents and visitors are strongly advised to use appropriate sun protection—such as sunscreen, hats, and sunglasses—especially during the high-risk months of January, February, and October through December.
UV Risk Categories
Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
Constantia | 14 | 13 | 11 | 8 | 5 | 3 | 4 | 6 | 9 | 11 | 12 | 14 |
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 |
Soweto UVI | 16 | 15 | 13 | 11 | 7 | 6 | 6 | 8 | 11 | 13 | 15 | 16 |