San Diego, California: vitamin D, best months and travel guide
Mild weather, calm beaches and a relaxed pace. Best for: families, couples.
The best months for vitamin D in San Diego are July to November, when a full dose takes about 7 minutes at midday. Too cool from December to June.
San Diego month by month
| Month | Rating | Sun window | Peak UV | Full dose, age 30 | Afternoon high | Rainy days |
|---|---|---|---|---|---|---|
| January | Too cold | 4.0 h | 3.7 | 14 min | 18°C | 6/30 |
| February | Too cold | 5.3 h | 4.8 | 11 min | 18°C | 5/30 |
| March | Too cold | 6.4 h | 6.0 | 9 min | 18°C | 7/30 |
| April | Too cold | 8.2 h | 7.4 | 7 min | 19°C | 0/30 |
| May | Too cold | 8.6 h | 8.0 | 7 min | 19°C | 1/30 |
| June | Too cold | 9.3 h | 8.3 | 6 min | 21°C | 0/30 |
| July | Excellent | 9.4 h | 8.1 | 7 min | 25°C | 0/30 |
| August | Excellent | 8.7 h | 7.8 | 7 min | 26°C | 0/30 |
| September | Excellent | 7.6 h | 6.9 | 8 min | 25°C | 0/30 |
| October | Good | 6.6 h | 5.7 | 9 min | 24°C | 0/30 |
| November | Good | 5.1 h | 4.4 | 12 min | 22°C | 2/30 |
| December | Too cold | 4.0 h | 3.7 | 14 min | 19°C | 0/30 |
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 Diego
Mild weather, calm beaches and a relaxed pace. The Pacific is cool all year. The south coast is sunny and pleasant, but May to June often brings morning fog (June Gloom). Summer is dry and warm, and winter can bring rain.
In San Diego afternoon highs average from 18°C in March to 26°C in August. The wettest month is March (about 7 rainy days out of 30) and the driest is December (0). Midday UV peaks at 8.3 in June, which is very strong, so protect your skin.
Balboa Park, Old Town, SeaWorld, San Diego Zoo, and nearby Tijuana, Mexico. (Wikivoyage, CC BY-SA 4.0)
More about California · California in July · Best places in July
Questions about San Diego
When is the best time to visit San Diego for vitamin D?
The best months for vitamin D in San Diego are July to November, when a full dose takes about 7 minutes at midday.
What is the weather like in San Diego?
Afternoon highs average from 18°C in March to 26°C in August. The wettest month is March, with about 7 rainy days out of 30.
Which months should I avoid in San Diego?
For a beach stay, avoid the months when it is too cool from December to June.