Studies of fire–atmosphere interactions in horizontally heterogeneous forests are limited in number. This study considers the sensitivity of fire-perturbed variables (e.g., vertical velocity, turbulent kinetic energy) to gaps in forest cover using ARPS-CANOPY, an atmospheric numerical model with a canopy sub-model. Results show that the atmosphere is most sensitive to the fire when the gap is centered on the fire and least sensitive when the gap is upstream of the fire.