Trunk Bay, U.S. Virgin Islands: vitamin D, best months and travel guide
National park beach with an underwater snorkel trail. Best for: snorkellers, families.
The best months for vitamin D in Trunk Bay are January to March, July, October, when a full dose takes about 6 minutes at midday. Rainy or stormy from April to June and from August to September and from November to December.
Trunk Bay month by month
| Month | Rating | Sun window | Peak UV | Full dose, age 30 | Afternoon high | Rainy days |
|---|---|---|---|---|---|---|
| January | Excellent | 7.1 h | 6.8 | 8 min | 27°C | 8/30 |
| February | Excellent | 7.0 h | 7.4 | 7 min | 26°C | 13/30 |
| March | Excellent | 8.4 h | 8.8 | 6 min | 27°C | 6/30 |
| April | Bad weather | 8.8 h | 9.1 | 6 min | 27°C | 22/30 |
| May | Bad weather | 8.9 h | 8.8 | 6 min | 29°C | 20/30 |
| June | Bad weather | 8.9 h | 8.6 | 6 min | 29°C | 18/30 |
| July | Excellent | 8.9 h | 8.8 | 6 min | 29°C | 16/30 |
| August | Bad weather | 8.8 h | 8.9 | 6 min | 29°C | 14/30 |
| September | Bad weather | 8.5 h | 8.6 | 6 min | 30°C | 19/30 |
| October | Excellent | 7.6 h | 7.5 | 7 min | 30°C | 14/30 |
| November | Bad weather | 6.1 h | 6.0 | 9 min | 28°C | 21/30 |
| December | Bad weather | 6.7 h | 6.2 | 9 min | 28°C | 19/30 |
Sun window is the number of hours a day with UV Index 2.5 or higher. Full dose is the minutes at midday for about 1,000 IU of vitamin D with a quarter of the body bare, for skin type III. Rainy days are days with at least 1 mm out of 30.
What to expect in Trunk Bay
National park beach with an underwater snorkel trail. A dry, pleasant season from December to April, and hurricane risk from June to November. US citizens need no passport, and driving is on the left.
In Trunk Bay afternoon highs average from 26°C in February to 30°C in October. The wettest month is April (about 22 rainy days out of 30) and the driest is March (6). Midday UV peaks at 9.1 in April, which is very strong, so protect your skin.
More about U.S. Virgin Islands · U.S. Virgin Islands in March · Best places in March
Questions about Trunk Bay
When is the best time to visit Trunk Bay for vitamin D?
The best months for vitamin D in Trunk Bay are January to March, July, October, when a full dose takes about 6 minutes at midday.
What is the weather like in Trunk Bay?
Afternoon highs average from 26°C in February to 30°C in October. The wettest month is April, with about 22 rainy days out of 30.
Which months should I avoid in Trunk Bay?
For a beach stay, avoid the months when it is rainy or stormy from April to June and from August to September and from November to December.