2D distribution of the wavelength-dependent optical-depth weighted mean particle radius, (μm). Note that cloud-free region in the dayside hemisphere is colored by light grey. The atmosphere of HAT-P-7b becomes optically thick due to small cloud particles on the nightside where ⟨a⟩ < 10⁻¹ … 10⁻²μm and due to large particles of ⟨a⟩ ≈ 1 μm on the morning terminator and in the higher latitudes.