In this paper, we continue the work on implicit–explicit (IMEX) time discretizations for the incompressible Oseen’s equations that we started in Burman et al. [Implicit–explicit time discretization for Oseen’s equation at high Reynolds number with application to fractional step methods, SIAM J. Numer. Anal. 61 (2023) 2859–2886]. The pressure velocity coupling and the viscous terms are treated implicitly, while the convection term is treated explicitly using extrapolation. Herein, we focus on the IMEX Crank–Nicolson method for time discretization. For the discretization in space we consider finite element methods with stabilization on the gradient jumps. The stabilizing terms ensure inf–sup stability for equal order interpolation and robustness at high Reynolds number. Under suitable Courant conditions, we prove the stability of the IMEX Crank–Nicolson scheme in this regime. The stabilization allows us to prove error estimates of order [Formula: see text]. Here [Formula: see text] is the mesh parameter, [Formula: see text] the polynomial order and [Formula: see text] the time step. Finally, we discuss some fractional step methods that are implied by the IMEX scheme. Numerical examples are reported comparing the different methods when applied to the Navier–Stokes’ equations.