Climate Seillans has a
hot-summer Mediterranean climate (
Köppen climate classification Csa). The average annual temperature in Seillans is . The average annual rainfall is with November as the wettest month. The temperatures are highest on average in August, at around , and lowest in January, at around . The highest temperature ever recorded in Seillans was on 7 August 2003; the coldest temperature ever recorded was on 20 December 2009. {{Weather box|width=auto ==Population==