Vitamin D in Portugal in January: sun, UV and what to expect
Too cold Too cold here in January: afternoon highs average only 16.1°C, which is too chilly for sunbathing in light clothing. Try another month or a warmer destination.
2.3 hsun window (UV 2.5+)
2.8peak UV Index
19 minto a full dose
16°Cafternoon high
10/30rainy days
24/30sunny days
How long in the sun in January?
- If you travel anyway, plan your sun session around midday (roughly 11:00 to 15:00), when the UV Index peaks at about 2.8. With about a quarter of your skin bare, a full dose takes around 19 minutes for skin type III at age 30, and about 36 minutes at age 65.
- Stop well before your skin turns pink. At this UV level skin type III can start to burn after about 71 minutes of midday sun, so cover up, find shade and use SPF 30+ on skin that stays out.
- Water, sand and light surfaces reflect UV, so at the beach you get a little more sun than the number suggests, for the good and the bad.
| Skin type | Full dose, age 30 | Full dose, age 65 | Time to burn |
|---|---|---|---|
| Type I | 13 min | 24 min | 48 min |
| Type II | 16 min | 30 min | 60 min |
| Type III | 19 min | 36 min | 71 min |
| Type IV | 29 min | 54 min | 1.8 h |
| Type V | 38 min | 71 min | 2.4 h |
| Type VI | 63 min | 2.0 h | 4.0 h |
Minutes at midday for about 1,000 IU of vitamin D with a quarter of the body bare, at Lisbon, the median coastal place. Time to burn is the time to reach one minimal erythemal dose and does not depend on age. A rough planning guide, not medical advice.
Places in Portugal in January
| Place | Rating | Sun window | Full dose | Afternoon high | Rainy days |
|---|---|---|---|---|---|
| Funchal | Too cold | 4.3 h | 13 min | 21°C | 7/30 |
| Algarve | Too cold | 2.7 h | 17 min | 18°C | 7/30 |
| Lagos | Too cold | 2.7 h | 17 min | 18°C | 8/30 |
| Albufeira | Too cold | 2.7 h | 17 min | 18°C | 8/30 |
| Faro | Too cold | 2.6 h | 18 min | 18°C | 7/30 |
| Lisbon | Too cold | 2.3 h | 19 min | 16°C | 10/30 |
| Cascais | Too cold | 2.2 h | 20 min | 16°C | 12/30 |
| Nazaré | Too cold | 1.6 h | 21 min | 16°C | 15/30 |
| Ponta Delgada | Too cold | 1.6 h | 21 min | 17°C | 23/30 |
| Porto | Too cold | 1.2 h | – | 16°C | 13/30 |
Other months in Portugal
- Jan Too cold
- Feb Too cold
- Mar Too cold
- Apr Too cold
- May Excellent
- Jun Excellent
- Jul Excellent
- Aug Excellent
- Sep Good
- Oct Good
- Nov Too cold
- Dec Too cold
Best months: May to October. Full Portugal guide