Last updated: May 3, 2025
Understanding the UV Index is crucial for residents of Utrecht, South Africa, where the climate can significantly influence sun exposure. Knowing the UV levels helps in preventing sunburn and protecting skin health, especially during the peak hours when the index rises to levels 5 and 7 around midday. Given Utrecht's Cwb climate, characterized by moderate temperatures and seasonal variations, awareness of UV radiation risks is essential for enjoying the outdoors safely. Whether you’re lounging in the sun or engaging in outdoor activities, staying informed about the UV Index can help safeguard your skin and overall well-being.
The UV Index data paints a clear picture of how exposure to ultraviolet rays varies throughout the day. Starting at a low level of 1 at 07:00, the index gradually climbs to peak at 7 from 11:00 to 12:00, indicating the times when sun protection is most crucial. As the afternoon progresses, the index dips to 6 at 13:00, then gently declines to 4 by 14:00. The evening hours see a significant drop, with values falling to 2 at 15:00 and retreating to 1 at 16:00. By nightfall, the UV Index drops to 0 from 18:00 onward, signalling a safe time for outdoor activities without the need for sun protection. Enjoy the sunshine, but be mindful of the peak hours!
| Time | UVI | Category | Time to Burn |
|---|---|---|---|
| 07:00 | 1 | low | 45 min |
| 08:00 | 2 | low | 45 min |
| 09:00 | 3 | moderate | 30 min |
| 10:00 | 5 | moderate | 30 min |
| 11:00 | 7 | high | 25 min |
| 12:00 | 7 | 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 |
The UV Index experiences significant seasonal variations, peaking during the winter months and into early spring. From January to March, the index remains at 15, categorizing exposure as extreme with a quick burn time of just 10 minutes. As spring approaches, April sees a slight decrease to 10, still marked as very high, with a burn time of 15 minutes. The summer months, particularly May and July, present high UV levels of 7 and 6, manageable with 25-30 minutes of exposure, while June dips to 5 (moderate). Moving into late summer, August rises again to 8 (very high) with a reduced burn time of 15 minutes. The danger resurfaces in September and October with 11 and 12 respectively, both extreme, requiring protective measures within 10 minutes. Finally, November and December escalate to 14 and 16 (extreme), emphasizing the need for caution during outdoor activities. Residents and visitors should take preventative precautions, especially in high-risk months from January to March, and again in September through December, by using sunscreen, wearing protective clothing, and seeking shade when necessary.
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 |
| Utrecht | 15 | 15 | 13 | 10 | 7 | 5 | 6 | 8 | 11 | 12 | 14 | 16 |
| 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 |