 According to the United States Census Bureau, the CDP covers an area of 6.0 square miles (15.6 km²), all of it land.According to the Köppen Climate Classification system, Lytle Creek has a warm-summer Mediterranean climate, abbreviated "Csa" on climate maps.A group of Mormons arrived in the valley in 1851, making camp at the mouth of a canyon with a creek, which flowed
briskly southeast through the canyon to the valley and the Santa Ana River.