Last updated: June 2, 2025
Understanding the UV Index is crucial for residents and visitors in Calvinia, South Africa, especially given the region's BWk climate characterized by high sun exposure. By keeping an eye on UV levels, individuals can effectively prevent sunburn and protect their skin health from harmful ultraviolet rays. With midday peaks reaching a UV Index of 4, it's essential to be proactive about sun safety—whether you're soaking up the sun or enjoying outdoor activities in this beautiful Karoo town.
The UV Index today starts low, with maximum values reaching 0 by 7:00 AM. As the sun rises, it gradually climbs to 1 at 8:00 AM and stays steady until 9:00 AM. By 10:00 AM, the index jumps to 2, marking the onset of more direct sunlight. The UV exposure peaks at 4 from 12:00 PM to 14:00 PM, signaling a critical time for sun protection. Following this peak, it dips back to 2 at 15:00 PM before easing further to 1 by 16:00 PM. Finally, the day wraps up with 0 UV exposure by 19:00 PM, making the late afternoon a much safer time for outdoor activities. Don't forget to apply sunscreen during the midday 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 | 4 | moderate | 30 min |
| 13:00 | 4 | moderate | 30 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 index levels fluctuate significantly, with the highest levels occurring in the winter months of January, February, and March, where the UV index reaches extremes of 15, 14, and 12, respectively, resulting in a burn time of just 10 minutes. As we transition into the spring, April sees a decrease to a very high index of 9, with a burn time extended to 15 minutes. May brings a high index of 6 (25 minutes burn time) and June and July remain moderate with indices of 4 and 5 respectively. August ramps back up to a high of 7, followed by September with a very high index of 10. As the year closes, October and November return to extreme levels of 12 and 13, with December matching January at a UV index of 15. Given this data, visitors and residents should be particularly cautious during January, February, March, and October to December, as these months present the highest risk for UV exposure. It is advised to seek shade, wear protective clothing, and apply sunscreen frequently during these high-risk months to mitigate the dangers of UV radiation.
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 |
| Calvinia | 15 | 14 | 12 | 9 | 6 | 4 | 5 | 7 | 10 | 12 | 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 |