Haikou, China: vitamin D, best months and travel guide
Provincial capital with an old street and the volcano park. Best for: short stays, culture travellers.
The best months for vitamin D in Haikou are January to March, October, November, when a full dose takes about 8 minutes at midday. Too hot in April and from June to August, too cool in December and rainy or stormy in May and in September.
Haikou month by month
| Month | Rating | Sun window | Peak UV | Full dose, age 30 | Afternoon high | Rainy days |
|---|---|---|---|---|---|---|
| January | Good | 4.4 h | 4.8 | 11 min | 23°C | 14/30 |
| February | Good | 5.3 h | 5.7 | 9 min | 26°C | 10/30 |
| March | Good | 6.2 h | 6.6 | 8 min | 28°C | 12/30 |
| April | Too hot | 8.2 h | 8.7 | 6 min | 35°C | 10/30 |
| May | Bad weather | 7.3 h | 7.6 | 7 min | 30°C | 28/30 |
| June | Too hot | 8.1 h | 7.8 | 7 min | 33°C | 26/30 |
| July | Too hot | 8.2 h | 8.2 | 7 min | 33°C | 26/30 |
| August | Too hot | 8.1 h | 8.1 | 7 min | 33°C | 22/30 |
| September | Bad weather | 6.4 h | 7.0 | 8 min | 30°C | 24/30 |
| October | Excellent | 6.8 h | 6.8 | 8 min | 28°C | 16/30 |
| November | Good | 5.3 h | 5.4 | 10 min | 25°C | 12/30 |
| December | Too cold | 4.1 h | 4.4 | 12 min | 22°C | 3/30 |
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 Haikou
Provincial capital with an old street and the volcano park. Hainan is warm all year, with a typhoon season from July to October. Qingdao and Xiamen have mild, humid summers. English is limited outside major hotels.
In Haikou afternoon highs average from 22°C in December to 35°C in April. The wettest month is May (about 28 rainy days out of 30) and the driest is December (3). Midday UV peaks at 8.7 in April, which is very strong, so protect your skin.
Questions about Haikou
When is the best time to visit Haikou for vitamin D?
The best months for vitamin D in Haikou are January to March, October, November, when a full dose takes about 8 minutes at midday.
What is the weather like in Haikou?
Afternoon highs average from 22°C in December to 35°C in April. The wettest month is May, with about 28 rainy days out of 30.
Which months should I avoid in Haikou?
For a beach stay, avoid the months when it is too hot in April and from June to August, too cool in December and rainy or stormy in May and in September.