Last updated: July 2, 2025
In Thornhill, South Africa, awareness of the UV Index is essential for safeguarding your skin health and preventing sunburn. Understanding UV levels is crucial for planning outdoor activities, as even moderate exposure can lead to skin damage over time. With its Cfb climate, Thornhill experiences varying UV risks throughout the day, peaking at a level of 4 around noon, when the sun’s rays are the strongest. By staying informed about the UV Index, you can enjoy the beautiful outdoors while ensuring your skin remains protected from harmful UV radiation.
The UV Index throughout the day reveals a dynamic pattern of sun intensity. In the morning, it starts off low, peaking at 1 by 09:00. As the sun climbs higher, we see a steady increase with the index reaching 3 by 11:00. The highest point occurs from 12:00 to 13:00, where the UV Index hits a robust 4, indicating a need for sun protection during those hours. Following this peak, the index gradually declines, returning to 2 at 15:00, and then dropping back down to 0 by 18:00, marking the end of significant UV exposure for the day. Plan your outdoor activities accordingly to stay safe under the sun!
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 | 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 |
Throughout the year, UV Index levels exhibit significant seasonal fluctuations, with extreme UV exposure occurring from January to March, where the index peaks at 14 in January and December. Visitors and residents should exercise caution during these months, as the burn time is as little as 10 minutes. The UV Index remains high in April, with a value of 8, before dropping to a moderate level of 5 in May and 4 from June to July. As summer wanes into August, the UV Index rises again to 6, prompting a high risk label, before returning to very high levels of 8 in September. The year closes with another spike in UV exposure, notably in October and November, where the index reaches 12, emphasizing the need for protective measures during these extreme periods. To safeguard against UV exposure, it's advisable for everyone to apply sunscreen and wear protective clothing, especially during the high-risk months.
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 |
Thornhill | 14 | 13 | 11 | 8 | 5 | 4 | 4 | 6 | 8 | 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 |