Besain (; Arpitan: Bësain) is a commune in the Jura department in the region of Bourgogne-Franche-Comté in eastern France.
On average, Besain experiences 116.4 days per year with a minimum temperature below , 11.2 days per year with a minimum temperature below , 9 days per year with a maximum temperature below , and 17.2 days per year with a maximum temperature above . The record high temperature was on 25 July 2019, while the record low temperature was on 2 January 1971.