 Grafton and three of her sisters were transferred to the Western Approaches Command at Plymouth in October. The following month, however, the ship was reassigned at the end of the month to the 22nd Destroyer Flotilla in Harwich of the Nore Command for patrol and escort duties. On 10 January 1940, she was transferred to the reconstituted 1st Destroyer Flotilla, also based at Harwich, where Grafton inspected ships travelling between German and Dutch ports for contraband. Between 26 March and 14 April the ship was given a brief overhaul in Hull in the shipyard of Brigham and Cowan. As the Norwegian Campaign had begun while Grafton was refitting, she was reassigned to the Home Fleet where she escorted convoys to Norway until 11 May.
