howmuchsun

Vitamin D from sunlight, by city

Your skin makes vitamin D only when the sun is high enough for UVB in the 295–315 nm band to reach the ground. Below that angle the ozone layer absorbs it, and no amount of time outside helps. That threshold depends on your latitude, the season and your elevation — so it differs for every city.

1,233 cities across 237 countries, each with its vitamin D winter dates, month-by-month exposure times and burn limits.

Browse by country