Live UV forecast for 6 cities
Guam stretches from 13.4476° to 13.5361° latitude (Northern hemisphere), so UV conditions differ a lot from region to region. The clear-sky UV index reaches ≈ 9.8 in Dededo Village (peak in April), while in Yigo Village the yearly maximum is only ≈ 9.8.
| Zone | Cities | J | F | M | A | M | J | J | A | S | O | N | D | Peak |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tropical | 6 | 7.9 | 8.6 | 9.4 | 9.8 | 9.8 | 9.7 | 9.7 | 9.8 | 9.7 | 9.1 | 8.4 | 7.8 | 9.8 |
Calculated clear-sky noon peaks at the average latitude of each zone. Real values vary with clouds, altitude and ozone.
Using Dededo Village 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 ≈ 9.8 — in Dededo Village around April. Values above this occur only near the equator and in high mountains.
Dededo Village (peak ≈ 9.8), followed by Hagatna and Mangilao Village. The mildest sun is in Yigo Village (max ≈ 9.8).
In Dededo Village 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 ≈ 9.8. UV 11+ occurs only near the equator, in deserts and high mountains.