An image recording apparatus, including: a holder on which a cartridge including a liquid chamber storing a liquid is mountable; a liquid-passage defining portion defining a liquid passage including a first end and a second end connected to the head, the first end configured to be connected to the liquid chamber when the cartridge is mounted on the holder; and a controller, wherein the controller is configured to divide a region in the liquid chamber occupied by the liquid into a plurality of regions in an up-down direction and determine a viscosity of the liquid in each region, based on a time elapsed from a timing of connection of the liquid chamber and the first end of the liquid passage, and wherein, when the liquid is discharged from the head, the controller updates the viscosity in each region, based on an amount of the liquid discharged from the head.