Live UV forecast for 304 cities
South Africa stretches from -34.583° to -22.3488° latitude (Southern hemisphere), so UV conditions differ a lot from region to region. The clear-sky UV index reaches ≈ 9.1 in Louis Trichardt (peak in December), while in Swellendam the yearly maximum is only ≈ 8.2. As in the whole Southern hemisphere, the sun is strongest from November to February — opposite to Europe and North America.
| Zone | Cities | J | F | M | A | M | J | J | A | S | O | N | D | Peak |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tropical | 6 | 9.1 | 8.9 | 8.3 | 7.3 | 6.4 | 5.8 | 6 | 6.9 | 7.8 | 8.6 | 9 | 9.1 | 9.1 |
| Subtropical | 298 | 8.5 | 8.2 | 7.5 | 6.3 | 5.3 | 4.6 | 4.8 | 5.8 | 6.8 | 7.8 | 8.3 | 8.5 | 8.5 |
Calculated clear-sky noon peaks at the average latitude of each zone. Real values vary with clouds, altitude and ozone.
Using Johannesburg as a reference: the UV index reaches 6+ in January, February, March, April, August, September, October, November and December. In the sunniest zones (see table) SPF 30–50+ is needed almost year-round; in the mildest — only in late spring and summer.
The calculated clear-sky maximum is ≈ 9.1 — in Louis Trichardt around December. Values above this occur only near the equator and in high mountains.
Louis Trichardt (peak ≈ 9.1), followed by Malamulele and Musina. The mildest sun is in Swellendam (max ≈ 8.2).
In Johannesburg and similar latitudes the UV reaches 6+ in January, February, March, April, August, September, October, November and December: use SPF 30–50+ on sunny days. Protection is advised from UV 3.
No — the local maximum is ≈ 9.1. UV 11+ occurs only near the equator, in deserts and high mountains.