  We investigate the axial $U(1)_A$ symmetry breaking above the critical
temperature in two-flavor lattice QCD. The ensembles are generated with
dynamical M\"obius domain-wall or reweighted overlap fermions. The $U(1)_A$
susceptibility is extracted from the low-modes spectrum of the overlap Dirac
eigenvalues. We show the quark mass and temperature dependences of $U(1)_A$
susceptibility. Our results at $T=220 \, \mathrm{MeV}$ imply that the $U(1)_A$
symmetry is restored in the chiral limit. Its coincidence with vanishing
topological susceptibility is observed.
