Live UV forecast for 448 cities
Indonesia stretches from -10.1708° to 5.8897° latitude (Southern hemisphere, partly crossing the equator), so UV conditions differ a lot from region to region. The clear-sky UV index reaches ≈ 10.9 in Bontang (peak in March), while in Waingapu the yearly maximum is only ≈ 10.1. 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Equatorial | 447 | 10.1 | 10.4 | 10.5 | 10.2 | 9.6 | 9.2 | 9.4 | 9.9 | 10.4 | 10.5 | 10.3 | 10 | 10.5 |
| Tropical | 1 | 9.9 | 10.1 | 10 | 9.4 | 8.8 | 8.3 | 8.5 | 9.1 | 9.7 | 10.1 | 10 | 9.9 | 10.1 |
Calculated clear-sky noon peaks at the average latitude of each zone. In the equatorial belt the UV stays high all year round, with two maxima around the equinoxes. Real values vary with clouds, altitude and ozone.
Using Jakarta as a reference: the UV index reaches 6+ in January, February, March, April, May, June, July, August, September, October, November and December. In the opposite-hemisphere regions the season is reversed. 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 ≈ 10.9 — in Bontang around March. Values above this occur only near the equator and in high mountains.
Bontang (peak ≈ 10.9), followed by Bukittinggi and Padangpanjang. The mildest sun is in Waingapu (max ≈ 10.1).
In Jakarta and similar latitudes the UV reaches 6+ in January, February, March, April, May, June, July, August, September, October, November and December: use SPF 30–50+ on sunny days. Protection is advised from UV 3.
No — the local maximum is ≈ 10.9. UV 11+ occurs only near the equator, in deserts and high mountains.