Lambert is a town in Quitman County, Mississippi. The population was 1,273 at the 2020 census. According to the United States Census Bureau, the town has a total area of 0.8 square miles, all land. The climate in this area is characterized by hot, humid summers and generally mild to cool winters. According to the Köppen Climate Classification system, Lam…Lambert is a town in Quitman County, Mississippi. The population was 1,273 at the 2020 census. According to the United States Census Bureau, the town has a total area of 0.8 square miles, all land. The climate in this area is characterized by hot, humid summers and generally mild to cool winters. According to the Köppen Climate Classification system, Lambert has a humid subtropical climate, abbreviated "Cfa" on climate maps.