The science is simple: as temperatures drop, deciduous trees stop producing chlorophyll, and - in the absence of the green pigment - their leaves change colours.
Some times the transformation from green to flaming orange, yellow or red is gradual, but on other occasions it's dramatic.
In the New England region of the US (discovernewengland.org), for instance, entire mountains, valleys and forests can go from deep green to fiery shades of gold and crimson overnight - just because Mother Nature plays her favourite trick: presses the "drop" button and sends temperatures suddenly plummeting one night.
Comprising the north-eastern states of Maine, Vermont, New Hampshire, Massachusetts, Connecticut and Rhode Island, New England is one of the most incredible places in the world to witness this dazzling phenomenon. Imagine going to bed with lush green views of a forest, only to wake up next morning in an amber-hued wonderland. No wonder, millions of "leaf peepers" - yes, that's what travellers obsessed with this spectacle are called - head here every year come September. Here are five other places where you can see the fall show.
Kyoto, Japan
Everyone knows about the soft pink cherry blossoms that mesmerise millions of locals and visitors in Japan every year in spring. But did you know about the ginkgos (the yellow leaves) and the momijis (the red leaves) that take centre stage in autumn?
One great place to find both these leaves is Kyoto, where vivid displays erupt in every direction and entire parks, temples, bridges and even still lakes get carpeted with these colourful leaves. Tofuku-ji, Nanzen-ji and Kiyomizu-dera are some of the best temples to visit between mid October and mid December, along with the laidback mountain village of Takao. kyoto.travel
Lake Louise, Canada
When it comes to natural beauty, this hamlet in Banff National Park in the Canadian Rockies is blessed with the lion's share. As if the turquoise lake, the steep mountains and the endless ski fields weren't enough, it also boasts thousands of larches - coniferous trees that shed their needles in autumn, transforming the landscape into myriad shades of golds, oranges and yellows from mid September to early October. Sign up for a hike or a horse-ride experience and weave your way through the towering trees, or - for a bird's-eye view - get on the Banff Gondola with vistas of six mountain ranges and the Bow Valley. banfflakelouise.com
Central Otago, New Zealand
Only a few hours' flight from Australia's east coast, the Central Otago region on New Zealand's South Island is well known for fiery autumn displays. Go leaf-peeping in Queenstown, where bright-yellow trees line the boardwalk along the gorgeous Lake Wakatipu - with the imposing Remarkables in the distance.
Then drive about 20 minutes south-west to Arrowtown, where an entire mountain begins to resemble an artwork in April and May, with pops of bright reds on a yellow canvas. Want more? Drive to Wanaka - about an hour south of Queenstown - for colourful sights at every turn along the way, and the ultimate prize at the end: views of a sole willow in the middle of Lake Wanaka. A social media sensation (#ThatWanakaTree), it goes yellow, too, this time of the year. centralotagonz.com
Aspen, Colorado
They flock to Aspen in ridiculously big numbers for the ski season in winter and for lakeside adventures in summer. Some have even discovered the resort town's spring-time charms - from gushing waterfalls to mountain hikes. But it is only the wisest travellers who visit Aspen in autumn, when hotels are mostly empty, restaurants aren't overbooked and the mountains are ablaze with bright yellow hues.
And if that doesn't convince you, here's the clincher: it's the best time to score a bargain in this very premium destination: from hotels to organised tours, plenty of discounts are on offer this time of the year. aspenchamber.org
Edinburgh, Scotland
It's not just about the colours here, it's about history, too. Imagine ancient castles clad in crimson vines, storybook bridges heaving with golden trees and medieval town centres with dramatic bronze accents. Enjoy a wander in the city to take in the spectacle between mid September and early November, ending up at the Arthur's Seat hill - less than three kilometres from the city centre - for panoramic views. edinburgh.org
Right here in Australia
No one puts the vast continent of Australia in the corner when it comes to autumn glory. Here are the four states with the finest displays.
1. Victoria: Dandenong Ranges, Macedon Ranges, Yarra Valley and characterful towns such as Ballarat and Daylesford ... there's no shortage of leaf-peeping locations in Victoria, but our pick would be Bright, where colourful hikes by day can be followed by delicious dinners - bursting with fresh autumnal produce - after dark.
2. NSW: In Australia's own New England - in northern NSW - at the right time of the year, you can see colours as vivid as in some parts of New England in the US. The Blue Mountains, the Southern Highlands, and towns of Bathurst, Orange and Oberon, offer spectacular sights, too.
3. Tasmania: From rich reds in Hobart's Royal Tasmanian Botanical Gardens to the flaming yellows of Huon Valley, the Apple Isle gets in the swing of things, too, come autumn, but one of the most exceptional experiences in Tasmania around that time is a hike through the Cradle Mountain-Lake St Clair National Park, when rich shades of yellow and orange add drama to an already striking landscape.
4. South Australia: Adelaide Hills is known for many things: history, culture, wines ... but thanks to the town of Stirling, and Mount Lofty Botanic Garden in Crafers, you can add fall foliage to the list, too.
- This article first appeared in Explore