howmuchsun

Vitamin D from sunlight in Latvia

How long you need in the sun to make vitamin D, and when the sun is too low to make any at all, for 2 cities in Latvia.

CityLatitudeElevationVitamin D winter
Riga 56.95°N 6 m 7 Sep – 17 Apr (223 days)
Daugavpils 55.88°N 103 m 11 Sep – 12 Apr (214 days)

How these dates are calculated