  Let $G$ be a connected semisimple real algebraic group and $\Gamma < G$ be a
Zariski dense Anosov subgroup with respect to a minimal parabolic subgroup. We
prove local mixing of the one-parameter diagonal flow $\{\exp(t\mathsf{v}) : t
\in \mathbb R\}$ on $\Gamma \backslash G$ for any interior direction
$\mathsf{v}$ of the limit cone of $\Gamma$ with respect to the
Bowen--Margulis--Sullivan measure associated to $\mathsf{v}$. More generally,
we allow a class of deviations to this flow along a direction $\mathsf{u}$ in
some fixed subspace transverse to $\mathsf{v}$. We also obtain a uniform bound
for the correlation function which decays exponentially in $\|\mathsf{u}\|^2$.
The precise form of the result is required for several applications such as the
asymptotic formula for the decay of matrix coefficients in $L^2(\Gamma
\backslash G)$ proved by Edwards--Lee--Oh.
