Climate Challes-les-Eaux has an
oceanic climate (
Köppen climate classification Cfb) closely bordering on a
humid subtropical climate (
Cfa). The average annual temperature in Challes-les-Eaux is . The average annual rainfall is with December as the wettest month. The temperatures are highest on average in July, at around , and lowest in January, at around . The highest temperature ever recorded in Challes-les-Eaux was on 31 July 2020; the coldest temperature ever recorded was on 14 January 1960. {{Weather box|width=auto ==Population==