  We consider natural inflation in a warm inflation framework with a
temperature-dependent dissipative coefficient $\Gamma \propto T^3$. Natural
inflation can be compatible with the Planck 2018 results with such warm
assistance. With no a priori assumptions on the dissipative effect's magnitude,
we find that the Planck results prefer a weak dissipative regime for our
benchmark scale $f=5 M_{\rm pl}$, which lies outside the $2\sigma$ region in
the cold case. The inflation starts in the cold regime and evolves with a
growing thermal fluctuation that dominates over quantum fluctuation before the
end of the inflation. The observed spectral tilt puts stringent constraints on
the model's parameter space. We find that $f< 1 M_{\rm pl}$ is excluded. A
possible origin of such dissipative coefficient from axion-like coupling to
gauge fields and tests of the model are also discussed.
