I always pictured an almost-rainy day when I listen to this one. I can see the clouds moving in, the sky darkening and the first droplets falling on the last crisp leave of fall, which twitch under the tiny impacts. The storm rises, but just as it appears to be a full blown shower, huge clouds part as the sun shines through, but only temporarily.
After but a brief moment of brilliant light reflecting off the shiny leaves, the rain returns, pummeling the final leaves to the ground. The song ends as the storm gradually moves off, leaving the trees now-barren against the threatening sky, a portend of the Winter to come.