The squadron was redesignated the 11th Air Corps Squadron, Weather, on 26 February 1942 and transferred to the 11th Air Force. On 28 May, it activated a weather station at Fort Glenn. In October, the squadron activated a weather station at Adak and its remotest station at St. Matthew Island. Now-Lieutenant Colonel Neal was transferred and replaced by Major Paul A. Carlson in November. A station at Amchitka was activated on 24 January 1943. After the American liberation of Attu in May, the squadron established a weather station at Alexai Point on the island. The Adak and Alexai Point stations provided forecasts for a number of bombing raids against Paramushir in the summer. By the end of 1943, the squadron controlled 32 weather stations, manned by 81 officers, seven NCOs, and 447 enlisted men, its peak strength. On 6 January 1944, the squadron became the 11th Weather Squadron. In February, both weathermen and a radio operator at the Chuginadak station died of exposure while searching for a supply barge which had run aground on the island. During the war, three men of the squadron received the Distinguished Flying Cross, seventeen received the Bronze Star, three were awarded the Army Commendation Medal, and five were awarded the Air Medal. The squadron was transferred to the Army Air Forces Weather Service (later the Air Weather Service) on 22 October 1945.