A room temperature curable organopolysiloxane composition comprising (A) a diorganopolysiloxane endcapped at both ends of the molecular chain with hydroxy group (HO—(R2SiO)n—H wherein R represents a monovalent hydrocarbon group, and n represents an integer of at least 10); (B) a silane having at least two dialkyl ketoxime groups in its molecule (R1x—Si(—O—N═CR2R3)4−x wherein R1 represents a monovalent hydrocarbon group, R2 and R3 represents a monovalent hydrocarbon group or R2 and R3 may together form a ring with the carbon atom to which they are bonded to, and x represents an integer of 0 to 2 and/or a partial hydrolysate thereof; (C) a filler selected from the group consisting of zinc carbonate, zinc oxide, zinc hydroxide, and mixtures thereof; (D) a curing catalyst; and (E) a hindered phenol compound having a molecular weight of at least 400.