Nukuʻalofa best: Excellent
Sleepy capital and the royal palace.
Vitamin D in Tonga: best months for sun and a travel guide
The best months for vitamin D in Tonga are April, June to September. In September, a full dose of about 1,000 IU takes around 7 minutes at midday for skin type III at age 30, with 7.0 usable sun hours a day. For a beach stay it is rainy or stormy in May and from October to March.
Tonga month by month
Tonga is rated at its median coastal place, for skin type III at age 30. Click a month for the details.
| Month | Rating | Sun window | Peak UV | Full dose, age 30 | Full dose, age 65 | Afternoon high | Rainy days |
|---|---|---|---|---|---|---|---|
| January | Bad weather | 7.9 h | 8.4 | 6 min | 12 min | 28°C | 24/30 |
| February | Bad weather | 8.4 h | 9.2 | 6 min | 11 min | 28°C | 28/30 |
| March | Bad weather | 5.8 h | 6.6 | 8 min | 15 min | 28°C | 26/30 |
| April | Excellent | 7.3 h | 7.0 | 8 min | 14 min | 28°C | 16/30 |
| May | Bad weather | 5.1 h | 5.3 | 10 min | 19 min | 26°C | 18/30 |
| June | Good | 5.5 h | 5.1 | 10 min | 20 min | 24°C | 13/30 |
| July | Good | 5.8 h | 5.4 | 10 min | 19 min | 24°C | 10/30 |
| August | Good | 6.0 h | 6.1 | 9 min | 16 min | 24°C | 14/30 |
| September | Excellent | 7.0 h | 7.4 | 7 min | 14 min | 24°C | 15/30 |
| October | Bad weather | 7.4 h | 7.7 | 7 min | 13 min | 25°C | 18/30 |
| November | Bad weather | 8.3 h | 8.7 | 6 min | 11 min | 26°C | 20/30 |
| December | Bad weather | 8.7 h | 9.0 | 6 min | 11 min | 29°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.
Travel guide: why go to Tonga
Why go
Tonga is a quiet kingdom where you can swim with humpback whales and enjoy empty, simple island life.
Best for
Whale watchers, sailors and adventurous couples.
What to expect
Humpback whale season is from July to October. The weather is warm, with a wetter season from November to April and cyclone risk. Sundays are strictly quiet.
Places in Tonga
Each place has its own climate, so its best months can differ from the country as a whole.
Questions about vitamin D in Tonga
When is the best time to visit Tonga for vitamin D?
The best months for vitamin D in Tonga are April, June to September. In September, a full dose of about 1,000 IU takes around 7 minutes at midday for skin type III at age 30, with 7.0 usable sun hours a day.
Can you get vitamin D from the sun in Tonga in May?
Yes, but slowly. In May a full dose takes about 10 minutes at midday for skin type III at age 30, with 5.1 usable hours a day.
How long do I need in the sun in Tonga?
In September, the best month, about 7 minutes at midday with a quarter of the body bare, for skin type III at age 30; about 14 minutes at age 65. Darker skin needs longer and fair skin burns sooner, so keep sessions short. This is an estimate for planning, not medical advice.
Which months should I avoid in Tonga?
For a beach stay, avoid the months when it is rainy or stormy in May and from October to March.
What is the best place in Tonga for vitamin D?
In September the strongest sun of the places we rate is around Neiafu. Each place has its own rating, so open the place list to compare them.
Plan by month
- Jan Bad weather
- Feb Bad weather
- Mar Bad weather
- Apr Excellent
- May Bad weather
- Jun Good
- Jul Good
- Aug Good
- Sep Excellent
- Oct Bad weather
- Nov Bad weather
- Dec Bad weather
Similar destinations
Best places for vitamin D in September · Vitamin D explained