Changing an entire map's sprites causes a momentary lag

Godot Version

4.2.2

Question

My game shows different sprites depending on the season.

Spring:

Summer:

Autumn:

Winter:

I drew 4 sprites to show the changes, and all nodes (sprite/tilemap/etc.) change sprites when the season changes.

if season changed:
    foo_node.texture = texture
    ...

The FPS/RAM/Process is pretty acceptable, but the physical process takes longer during the season change, so I can feel a slight lag in the game.

Is there any way to improve it?