IN PLACES WHERE the first snow of the season falls as early as October, preparations for winter begin in August. On the coasts of Norway and Sweden, boats are pulled ashore and stored safely so they’re not damaged by winter storms. Wooden planks are oiled, the last potatoes are dug up and tucked away in a dry place, and flower beds are mulched with seaweed. Windowpanes in seasonal homes are covered with paper to prevent birds from accidentally flying into them. People leave their summer houses but don’t lock them, so that those seeking shelter can find a place to stay in case of emergency and fortify themselves with the frugal supplies. A thoughtful gesture.

      Some people, as much as they might have looked forward to cold and clear winter air during the heat of summer, become melancholy when the season arrives. Other people hope to find time to rest. Still others studiously devote themselves to seasonal tasks. Is the heating in good working order? Are the window seals clean? Is the roof or the outside of the house in need of repair? Is the water in the garden drained and shut off? Are the pipes near the house well insulated so they won’t freeze, break, and flood interior spaces? Are the gutters clear of foliage, needles, and moss? Is there enough sand or salt to scatter on the driveway? Are winter tires required? A ladybug that would normally winter in a sheltered nook outside flies into the house, clearly hoping to shelter there for the cold season.

      When the time comes, the air gets cooler, the light gets weaker, and the days get noticeably shorter. Winter is on its way—we can feel it in our bones—but it isn’t quite upon us yet. The sky is gray. Migratory birds have been gone for a while now. It rains, sometimes for days. It’s a time of transition, of in-between seasons. In London, Alfred Alvarez swims almost daily in the ponds of Hampstead Heath, even though he is well into his eighties. On November 8 it is fifty degrees Fahrenheit (10°C). He notes: “Today feels like the first day of winter—no colder than yesterday, but dark and windy and raining hard—the sort of day when you grit your teeth before you take off your clothes. But the temperature of the water hasn’t changed—it’s more refreshing and delicious than chilly—so maybe gritting your teeth is part of the pleasure.”

      At first, the transition takes place in small, as-yet-imperceptible steps. There’s a delicate, cold prewinter drizzle. A bottle half-filled with water and forgotten in the garden shatters on a cold night. Leaves coated with delicate needles of hoarfrost glitter in the sunlight. A few nights later, the first snow falls, and myriad crystals of endless complexity reflect the glow of the streetlights, brightening the room. And, aside from the occasional cracking of trees as sap freezes, it’s much quieter. It’s said you sleep more deeply when there is snow on the ground. The Japanese language has an expression for the first snowfall of a new winter: hatsuyuki.

      Only the most diehard still feel drawn to the outside, either out of necessity or to experience the particular pleasures of the crisp, cold air. People brave biting winds to check traplines, chop through ice to keep water and fishing holes open, or crawl into holes scraped in the snow to survive the night. They plummet down precipitous slopes on skis, glide over frozen lakes on skates, or trudge on snowshoes under the soft white light of a full moon. Children build snow forts and pelt each other with snowballs. Adults draw their chairs around a crackling fire, closing the curtains against the dark, hands cradling steaming mugs as they share stories that bring families and communities closer together. In the cold of winter.

      The season people know as winter is laden with meanings and customs that are influenced by culture, latitude, and altitude. Every country outside the tropical zones is familiar with it, and yet in each climate zone it manifests itself somewhat differently: farther north—whether in Scandinavia, Siberia, Alaska, or Canada, and with all the peculiarities and particularities of geography and climate in those regions—winter is at its most extreme.

      Daylight becomes a precious resource at higher latitudes. The shortest day of the year in Barrow, Alaska, the northernmost point in the state, lasts for just three hours and forty-two minutes, and on that day the sun doesn’t even rise above the Arctic Circle. Mountains exacerbate the effect of dwindling winter light. In Norway, villages in valleys surrounded by steep mountains are cast in shadow for almost six months of the year. In 2013, in the southern Norwegian town of Rjukan, people placed three large mirrors above the city to redirect sunlight into the valley and onto the faces of the people living there. This was a first for the city and was understandably celebrated as a historic event. Incidentally, the idea for using mirrors originally came up more than a hundred years ago, though before Rjukan, no town had attempted to put it into practice.

      In the almost endless night of northern winters, snow brightens the landscape as it reflects the light of the moon and the stars, making the darkness more bearable. Where snow lingers for four to five months, trees sag under its weight. From a distance, snow-clad conifers look like huge, irregularly formed candles dripping with wax. Even farther north, the stunted growth of trees and shrubs levels the landscape, stripping it of its features.

      The Arctic receives less than ten inches (25 centimeters) of precipitation a year, making it technically a desert, and the air there is surprisingly still and clear. Cold air absorbs very little moisture, which means that barely any snow falls in extremely low temperatures. If and when storms rage, however, the snow they bring remains on the ground for a long time due to the unremitting cold.

      The Antarctic holds more than two-thirds of the Earth’s fresh water in its thick shields of ice, but it, too, experiences very low snowfall because of the extremely cold temperatures that dominate the region year-round. With so little change in the landscape, time appears to stand still. The cold has a lock on vast stretches of land that thaw only briefly during the summer. By drilling down more than ten thousand feet (3,000 meters), scientists have collected ice cores that are approximately 900,000 years old and contain data spanning more than eight ice ages.

      In some places in the North, however, it’s not as cold as you might suppose: on Bjørnøya (Bear Island), which is situated between Norway’s North Cape and the Svalbard archipelago, the average temperature during the winter months is a mild fourteen degrees Fahrenheit (−10°C). In the northeast of Greenland, by contrast, the temperature is minus four Fahrenheit (−20°C). These are averages, of course; the coldest temperatures measured at a particular place are significantly lower. For Alaska, that number is minus eighty (−62.2°C), narrowly beaten out by Snag, Yukon, in Canada, at minus eighty-one (−62.8°C). Many northern communities depend on freezing temperatures so people can hunt by sled and snowmobile and supplies can come in by truck. Lack of snow, melting permafrost, and unpredictable ice cover on lakes actually isolate them even further. For people here, the real problem is not enough winter, rather than too much.

      Although winter and snow are often thought of as being practically synonymous, winter is only indivisibly bound to snow in northern Europe, Russia, Alaska, and Canada, and in many mountainous regions. As you move south, the character of winter transforms dramatically. In certain regions of Central Europe today, snow fails to appear at all. In the Mediterranean, southern California, and Florida, summers on average are hotter and longer, which means winters are even shorter and milder than they once were. There’s a certain irony to plastic snowmen standing on balconies in Rome, “White Christmas” blaring from shopping-mall loudspeakers in the Sunshine State of Florida, or log-cabin holiday markets in London where most of the snow decorating the scene is artificial. Nevertheless, even in the Mediterranean, cold snaps can surprise inhabitants and leave their mark—not only in the French Maritime Alps, but also at much lower