Mean stratification of the temperature gradient 〈dT/dτ〉_τ averaged over surfaces of the constant Rosseland optical depth and time of the G2V (left column), K0V (middle), and M2V (right) stars. Top row: mean temperature gradient 〈dT/dτ〉_τ computed from the simulations run using the 18OB (black curve), 4OB (blue), and grey (red) opacity setups. Bottom row: absolute difference of 〈dT/dτ〉_τ computed with 4OB (blue curve) and grey (red) compared to 〈dT/dτ〉_τ obtained using 18OB.