San Juan, Puerto Rico: vitamin D, best months and travel guide
Blue-cobbled old city with forts and a lively restaurant scene. Best for: couples, history fans, foodies.
The best months for vitamin D in San Juan are March, October, December, January, when a full dose takes about 6 minutes at midday. Rainy or stormy in February and from April to September and in November.
San Juan month by month
| Month | Rating | Sun window | Peak UV | Full dose, age 30 | Afternoon high | Rainy days |
|---|---|---|---|---|---|---|
| January | Good | 6.9 h | 6.4 | 8 min | 30°C | 6/30 |
| February | Bad weather | 7.0 h | 7.2 | 7 min | 28°C | 19/30 |
| March | Excellent | 8.2 h | 8.5 | 6 min | 30°C | 15/30 |
| April | Bad weather | 8.5 h | 8.6 | 6 min | 30°C | 25/30 |
| May | Bad weather | 8.5 h | 8.6 | 6 min | 31°C | 25/30 |
| June | Bad weather | 8.8 h | 8.7 | 6 min | 32°C | 21/30 |
| July | Bad weather | 8.8 h | 8.6 | 6 min | 32°C | 19/30 |
| August | Bad weather | 8.6 h | 8.7 | 6 min | 32°C | 21/30 |
| September | Bad weather | 8.4 h | 8.5 | 6 min | 33°C | 25/30 |
| October | Excellent | 7.4 h | 7.5 | 7 min | 33°C | 15/30 |
| November | Bad weather | 6.6 h | 6.3 | 8 min | 30°C | 23/30 |
| December | Good | 6.6 h | 6.0 | 9 min | 29°C | 17/30 |
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 San Juan
Blue-cobbled old city with forts and a lively restaurant scene. A dry season from December to April and a hot, humid, stormy season from June to November. US citizens need no passport. Spanish is the main language, though English is common in tourist areas.
In San Juan afternoon highs average from 28°C in February to 33°C in October. The wettest month is April (about 25 rainy days out of 30) and the driest is January (6). Midday UV peaks at 8.7 in June, which is very strong, so protect your skin.
More about Puerto Rico · Puerto Rico in March · Best places in March
Questions about San Juan
When is the best time to visit San Juan for vitamin D?
The best months for vitamin D in San Juan are March, October, December, January, when a full dose takes about 6 minutes at midday.
What is the weather like in San Juan?
Afternoon highs average from 28°C in February to 33°C in October. The wettest month is April, with about 25 rainy days out of 30.
Which months should I avoid in San Juan?
For a beach stay, avoid the months when it is rainy or stormy in February and from April to September and in November.