He flew his first combat missions in Operation Barbarossa, the German invasion of the Soviet Union, and claimed his first aerial victory on 26 June 1941.

Lemke was subsequently relocated to the Western Front, where he flew in the Defense of the Reich and claimed six further victories.

Lemke was killed in action on 4 December 1943 northwest of Nijmegen in combat with United States Army Air Forces fighters.

Lemke, the son of a civil servant, was born on 27 September 1920 in Gundelsdorf near Arnswalde, in what was then the Free State of Prussia of the Weimar Republic (today Choszczno in Poland).

[3][Note 1] Lemke was posted to a front-line unit in 1941, almost two years after the start of World War II.

[3] On 11 July, his wingman and Staffelkapitän (squadron leader), Oberleutnant Winfried Schmidt was severely wounded in combat near Fastiv.

By talking to Schmidt over the radio, Lemke managed to guide him back to the airfield at Polonne.

On this day, flying Messerschmitt Bf 109 F-2 (Werknummner 8245—factory number), he was hit and wounded in the abdomen during combat with Soviet bombers but managed to make an emergency landing.

[9] He claimed three Lavochkin-Gorbunov-Gudkov LaGG-3 fighters shot down in combat with 6 UAG (6th Soviet strike aviation group—Udarnaya Aviatsionnaya Gruppa) on 4 April.

[9] On 2 August 1943, JG 3 "Udet" began transferring to Western Front and flew in Defense of the Reich.

The Gruppe arrived at Münster-Handorf Airfield the following day where they were placed under its new commander Hauptmann Walther Dahl.

[16] Lemke claimed two USAAF Republic P-47 Thunderbolt fighters shot down on 17 August during the Schweinfurt–Regensburg mission, his first on the Western Front.

Staffel to Leutnant Ekkehard Tichy and took command of the Gruppe a few days later at the Schiphol airfield, near Amsterdam in the Netherlands.

[22] Lemke was killed in action in his Bf 109 G-6 (Werknummner 410558) on 4 December 1943 near Dodewaard, 12 kilometers (7.5 mi) northwest Nijmegen.

[26] Obermaier and Stockert also list Lemke with 131 aerial victories claimed in 617 combat missions, 125 of which were on the Eastern Front and included 28 Ilyushin Il-2 ground-attack aircraft.