Hana, Hawaii: vitamin D, best months and travel guide
Remote road-trip destination of waterfalls and black sand. Best for: adventurers, couples.
Hana gives little vitamin D from the sun in any month for skin type III at age 30. Rainy or stormy all year.
Hana month by month
| Month | Rating | Sun window | Peak UV | Full dose, age 30 | Afternoon high | Rainy days |
|---|---|---|---|---|---|---|
| January | Bad weather | 6.2 h | 5.9 | 9 min | 25°C | 20/30 |
| February | Bad weather | 5.7 h | 5.5 | 10 min | 23°C | 28/30 |
| March | Bad weather | 6.3 h | 5.7 | 9 min | 23°C | 30/30 |
| April | Bad weather | 7.1 h | 6.1 | 9 min | 23°C | 30/30 |
| May | Bad weather | 7.4 h | 6.4 | 8 min | 25°C | 28/30 |
| June | Bad weather | 8.2 h | 7.1 | 8 min | 25°C | 25/30 |
| July | Bad weather | 8.2 h | 7.7 | 7 min | 26°C | 30/30 |
| August | Bad weather | 7.8 h | 7.6 | 7 min | 26°C | 30/30 |
| September | Bad weather | 7.6 h | 7.3 | 7 min | 27°C | 28/30 |
| October | Bad weather | 6.7 h | 6.3 | 8 min | 26°C | 25/30 |
| November | Bad weather | 5.5 h | 4.8 | 11 min | 25°C | 26/30 |
| December | Bad weather | 5.9 h | 5.3 | 10 min | 25°C | 20/30 |
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 Hana
Remote road-trip destination of waterfalls and black sand. Warm all year, with a drier summer on the leeward sides and a wetter, bigger-surf winter from November to March. UV is very strong, and reef-safe sunscreen is advised. Prices are high.
In Hana afternoon highs average from 23°C in March to 27°C in September. The wettest month is March (about 30 rainy days out of 30) and the driest is December (20). Midday UV peaks at 7.7 in July.
Questions about Hana
When is the best time to visit Hana for vitamin D?
Hana gives little vitamin D from the sun in any month for skin type III at age 30.
What is the weather like in Hana?
Afternoon highs average from 23°C in March to 27°C in September. The wettest month is March, with about 30 rainy days out of 30.
Which months should I avoid in Hana?
For a beach stay, avoid the months when it is rainy or stormy all year.