Key points: Pilots should maintain knowledge and skills required to avoid unintentional operations in IMC; If a VFR-rated pilot does find themselves in marginal weather, they should seek whatever assistance is available, including contacting air traffic services. An incident that saw a student pilot and instructor in a Piper PA-28 encounter deteriorating weather and enter instrument meteorological conditions (IMC) while operating under visual flight rules (VFR) highlights the importance of thorough pre-flight planning, an Australian Transport Safety Bureau investigation notes. The student pilot (in the left seat) and instructor (in the right hand seat), with a second student pilot (seated in the rear) observing, were conducting a navigation training flight in the PA-28 from Melbourne’s Moorabbin Airport to Warrnambool in western Victoria and return on 25 February 2021, as part of the student’s integrated commercial pilot licence training.