A display apparatus mountable on a mobile object, which: obtains a display location and a movement direction of a virtual object to be displayed in a display area of the display apparatus so as to be overlaid in a real world, the virtual object to be moved relative to movement of the mobile object; estimates a time it will take for the virtual object to move from the display location to a border of the display area, or a distance between the display location of the virtual object and the border of the display area, each based on the display location and the moving direction of the virtual object; determines a display form of the virtual object based on the estimated time or the estimated distance; and causes the virtual object be displayed in the determined display form, such that the virtual object changes the display form while moving in the display area.