One day only · The fall foliage lab
Autumn is peaking. Find your colour.
Right now the great colour wave is rolling south across the Northern Hemisphere — high peaks first, then the valleys, then the South. Track it, learn the science behind it, and play with the leaves.
Loading today's foliage…
🍁 The foliage pulse
Open the full chart →Peaking this week
Where are you headed?
Type a park, state or country to jump straight to its peak window.
Three ways to play
A whole lab for one season
Leaf ID game
Name twenty hand-drawn leaves across four modes — Classic, Expert, Streak and a timed Speed round. Build a collection and share your score.
Play →Pigment Lab
Slide chlorophyll, carotenoids, anthocyanins and tannins to build a leaf's colour, add weather, then turn it into a shareable autumn palette.
Mix colours →Field Guide & quiz
Thirty-plus autumn trees with their palettes and leaf shapes, a five-second leaf-shape primer, and a shuffled quiz on the whole season.
Explore →Why leaves change
Two things happen at once
The green disappears — and reds may be built from scratch. Everything else is weather.
Chlorophyll fades
As days shorten, the leaf stops making food. The green chlorophyll breaks down, revealing yellow and orange carotenoids that were there all along.
Anthocyanins are made
Sunny days and cool nights trap sugar in the leaf, which is turned into red and purple anthocyanins — the recipe for the brightest maples.
Then the leaf lets go
An abscission layer seals the stem, the leaf drops, and a leaf scar is left behind. Oaks often hold their brown leaves all winter.