  The thermal properties of light mesons, including the temperature dependence
of their masses(both screening and pole masses) and thermal widths, are studied
in a two-flavor ($N_f=2$) soft-wall AdS/QCD model. By solving the spatial
correlation functions, we extract the screening masses ($m_{\rm{scr}}$) from
their poles. The screening masses of pseudo-scalar (pion), axial-vector ($a_1$)
mesons increase (almost)monotonically with the temperature, while the screening
masses of scalar ($\sigma$) and vector ($\rho$) mesons decrease at low
temperatures and increase at high temperatures. Besides, the pole masses
($m_{\rm{pole}}$) and thermal widths ($\Gamma$) are worked out from the
temporal correlation functions and the corresponding spectral functions. The
results indicate that the pole masses have local minimums at low temperatures
and grow at high temperatures. The thermal widths grow rapidly above the chiral
crossover temperature $T_{cp}$, indicating the dissociation of mesons at high
temperatures. Furthermore, degeneration of chiral partners (pion and $\sigma$
mesons, $\rho$ and $a_1$) above $T_{cp}$ are observed both from screening
masses and pole masses, revealing the restoration of chiral symmetry at the
spectral level. Finally, we verify numerically that the spectral functions in
the temporal regime are strongly related to the quasi-normal modes with complex
frequencies $\omega_0=m_{\rm{pole}}-i \Gamma/2$.
