"Stembel" sailed for San Pedro on 21 January and thence proceeded to Ulithi. She sortied from there on 10 February in the screen of the Amphibious Support Force for the invasion of the Volcano Islands. After staging off Saipan, the DD arrived off Iwo Jima on 16 February where she screened minesweepers, conducted night harassment fire, bombarded the beaches for the troops as they landed, and then supported them with call fire until 7 March. After making voyage repairs at Ulithi "Stembel" joined the fast carriers and sortied, on 14 March, for an area east of Kyūshū. Air strikes were flown against that island on 18 March; and, on 19 March, against Kyūshū airfields as well as against shipping at Kure and Kobe, Honshū. "Stembel" rescued two men from a downed plane from "Wasp" (CV-18) on 18 March and splashed an enemy aircraft the next day.