We establish an asymptotic profile that sharply describes the behavior as t→∞ for solutions to a non‐solenoidal approximation of the incompressible Navier–Stokes equations introduced by Temam. The solutions of Temam's model are known to converge to the corresponding solutions of the classical Navier–Stokes, for example, in L loc 3false(double-struckR+×double-struckR3false), provided ε→0, where ε>0 is the physical parameter related to the artificial compressibility term. However, we show that such model is no longer a good approximation of Navier–Stokes for large times: indeed, its solutions can decay much slower as t→∞ than the corresponding solutions of Navier–Stokes.