As summer fades, trees prepare for winter by slowing down chlorophyll production — the pigment that makes leaves green. Without chlorophyll, other pigments like carotenoids and anthocyanins become visible, painting landscapes in warm hues.

Weather plays a key role: sunny days and cool nights intensify reds, while overcast conditions can mute the palette. Scientists say climate change may alter these patterns, making each autumn’s display a unique and fleeting spectacle.