Live UV forecast for 5 cities
French Guiana stretches from 4.8492° to 5.5015° latitude (Northern hemisphere), so UV conditions differ a lot from region to region. The clear-sky UV index reaches ≈ 10.5 in Cayenne (peak in April), while in Saint-Laurent-du-Maroni the yearly maximum is only ≈ 10.5.
| Zone | Cities | J | F | M | A | M | J | J | A | S | O | N | D | Peak |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Equatorial | 5 | 9.4 | 9.9 | 10.4 | 10.5 | 10.2 | 9.9 | 10 | 10.4 | 10.5 | 10.3 | 9.8 | 9.3 | 10.5 |
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 Cayenne as a reference: the UV index reaches 6+ in January, February, March, April, May, June, July, 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 ≈ 10.5 — in Cayenne around April. Values above this occur only near the equator and in high mountains.
Cayenne (peak ≈ 10.5), followed by Kourou and Matoury. The mildest sun is in Saint-Laurent-du-Maroni (max ≈ 10.5).
In Cayenne 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 ≈ 10.5. UV 11+ occurs only near the equator, in deserts and high mountains.