Hot and Cold Places of the World

Earth is round like a ball. A globe is a small model of Earth. You can turn it to follow land and oceans.

Find three starting places

The North Pole is Earth's farthest-north point. The South Pole is its farthest-south point. Most globes show north at the top. In space, Earth has no real top or bottom.

The equator circles Earth's middle, halfway between the poles. It is an imaginary line. You see it drawn on maps, but not painted across the ground. Near Quito, Ecuador, a monument marks the area where it passes.

The equator divides Earth into two halves, called hemispheres. North of it is the Northern Hemisphere. South of it is the Southern Hemisphere. Canada, Europe, and the United States are north of the equator. Australia, New Zealand, and Antarctica are south of it.

Trace a path on a globe

1. Find the North Pole at the northern end.
2. Slide your finger toward the middle. Stop at the equator.
3. Keep moving south until you reach the South Pole.
4. Find your country. Check which side of the equator it is on.

Now compare Miami and Anchorage. Both are north of the equator. Miami, Florida, is much closer to the equator. Anchorage, Alaska, is closer to the North Pole. Minneapolis, Minnesota, lies almost halfway between them. Being in the same half of Earth does not mean being equally far north.

Follow the equator around Earth

The line crosses land in South America, Africa, and Asia. You can trace it through Brazil, Kenya, and Indonesia. Much of the line crosses the Pacific, Atlantic, and Indian Oceans. It misses North America, Europe, Australia, and Antarctica.

The Arctic surrounds the North Pole. Antarctica surrounds the South Pole. Their names sound alike, but they are at opposite ends of Earth.

A flat world map shows the whole Earth on a page. Flattening a round world stretches some places. Greenland may look nearly as large as Africa on a map. Africa is actually about 14 times larger. Use a globe when you want to compare their shapes and sizes.

Sunlight warms land, water, and air. The way it reaches the ground helps explain Earth's hot and cold places.

Follow a beam of sunlight

Near the equator, the midday sun is high overhead. Its rays arrive almost straight down throughout the year. The light warms a fairly small patch strongly.

Near either pole, the sun stays low in the sky. The rays arrive at a slant. The same light spreads across a larger patch. Each part gets less warmth. Slanting rays also travel through more air before reaching the ground.

Try the flashlight model

Use a flashlight and a sheet of paper. Keep the flashlight about the same distance from the paper.

1. Point the beam straight down. Look at the small, bright patch.
2. Tilt the beam sideways. The patch becomes longer and dimmer.
3. Compare the patches. The tilted beam spreads its light farther.

The first patch models sunshine near the equator. The second models sunshine near the poles. The flashlight has not become weaker. Its light is simply spread over more paper.

Why polar winters are so cold

In polar winter, the sun may stay below the horizon for weeks. At each pole, daylight lasts about six months. Darkness then lasts about six months. Without sunshine, the ground gets very little warmth from the sun. White snow and ice also reflect much sunlight back toward the sky.

The poles are not cold because they are much farther from the sun. The sun is about 93 million miles away. The small distance difference across Earth does not explain the cold. Earth is actually closest to the sun in early January. That is winter in the Northern Hemisphere.

Look for the pattern and the mountain

Start at the equator and travel north. Places usually get colder as you approach the North Pole. Travel south from the equator, and the same pattern appears.

Height matters too. High mountains are colder than nearby low ground. Mount Kilimanjaro in Tanzania stands near the equator. Yet snow and ice lie on its high top. The Andes in Ecuador have snowy peaks too.

Heat and rain are different clues. A low place near the equator is usually hot. It might have rain all year or separate wet and dry seasons.

A snowy morning tells you about today's weather. A place's climate is its usual weather over many years. One cold day does not turn a warm place into a polar place.

Read the bands around Earth

We can group places into three main kinds of climate zone. On a globe, these make five bands.

There is one hot band, two temperate bands, and two polar bands. Starting at the North Pole, the order is cold, temperate, hot, temperate, cold.

The hot zone is also called the tropics. Some tropical places are rainy all year. Others have a wet season and a dry season. Singapore and Hawaii are in this zone. Low places there have no snowy winter.

Find the named lines

The Tropic of Cancer marks the northern edge of the tropics. The Tropic of Capricorn marks the southern edge. The equator lies between them.

The Arctic Circle marks the northern polar region. The Antarctic Circle marks the southern one. Inside these circles, some summer days have no sunset. Some winter days have no sunrise.

Sort three places

Start with Singapore. It is close to the equator and hot all year. Put it in the hot zone.

Next, find Chicago, Illinois. It lies between the tropics and the northern polar region. Its year has spring, summer, fall, and winter. Put it in a temperate zone.

Finally, find Utqiaġvik, Alaska. It lies north of the Arctic Circle. Long, freezing winters place it in the cold polar zone.

Temperate does not mean warm every day

Most of the United States, much of Europe, New Zealand, and southern Australia are temperate. Their seasons can feel very different. In Minneapolis, winter days can fall below 0 °F (about −18 °C). Summer days can rise above 90 °F (about 32 °C). San Francisco has much gentler changes, with cool summers and mild, rainy winters.

Zone lines are not walls. Conditions change gradually across the land. Mountains, oceans, and winds also shape a place's climate. Dry deserts can lie in different zones.

The polar regions surround Earth's two poles. Both have ice and cold weather. Look under the ice to tell them apart.

Ocean in the north, land in the south

The Arctic surrounds the North Pole. At its center is the Arctic Ocean, with floating sea ice. Northern parts of North America, Europe, and Asia surround it. Greenland, Earth's largest island, lies in the Arctic. A huge ice sheet covers most of Greenland.

Antarctica is land around the South Pole. It is the fifth-largest continent, bigger than the United States. An ice sheet covers almost all of it. In many places, that ice is more than a mile thick. The Southern Ocean surrounds the continent.

Antarctica is the coldest continent. Much of it is high land covered in ice. The Arctic has ocean water beneath its sea ice. That water is less cold than the air and helps soften the cold. At Vostok Station, a thermometer recorded −128.6 °F (−89.2 °C) on July 21, 1983. This is the world record for the lowest measured air temperature.

Tell the ice apart

Most of an iceberg stays hidden beneath the water. Floating ice can have different beginnings: freezing seawater or broken land ice.

A very different day

In Utqiaġvik, Alaska, the sun sets in mid-November. It does not rise again until late January, about two months later. In summer, almost three months pass without a sunset. This summer daylight is called the midnight sun.

Cold, treeless tundra stretches around parts of the Arctic Ocean. Much of it has permafrost, ground frozen for at least two years. In summer, the top layer thaws. Small plants, mosses, and flowers grow quickly. Lichens cover rocks, and birds and insects arrive.

Keep the two ends separate

Polar bears live in the Arctic. Wild penguins do not. Almost all penguins live in the southern half of Earth.

Most of Earth's fresh water is frozen in Antarctica's ice. Yet its middle receives very little new snow. That makes it a cold desert. In the Arctic, summer sea ice is shrinking as the region warms. Polar bears lose places where they hunt seals.

An animal's home can be freezing, windy, and hard to cross. An adaptation is a feature or behavior that helps it survive there. Animals inherit body features; they do not choose to grow them.

Keep body heat inside

Thick fur and tightly packed feathers hold warmth close to the body. Many sea animals have blubber, a thick fat layer under their skin. Seals, walruses, and whales use it to stay warm in icy water. Polar bears have thick fur, black skin underneath, and body fat.

Small ears lose less warmth than large ears. An Arctic fox has small, rounded ears. Its thick tail can cover its face while it rests. A desert fennec fox has large ears that help release heat. Each feature helps with a different problem.

Hide and move

An Arctic fox or hare grows white fur in winter. Brown or gray summer fur matches the ground after snow melts. Blending into the background is camouflage. A polar bear's pale fur helps it approach seals unseen.

Wide feet help animals cross snow. Polar bears spread their weight over huge paws. Rough pads help them grip. Caribou have broad hooves that work like snowshoes.

Behaviors help too

• Emperor penguins huddle together during the Antarctic winter. They take turns at the cold outside edge.
• Arctic terns migrate, traveling between the Arctic and Antarctic each year.
• Arctic ground squirrels hibernate. Their bodies cool, and their heartbeat and breathing slow greatly. This saves energy when food is scarce.

Hibernation is a body change, not ordinary sleep. Penguins cannot fly, but they swim well. An emperor penguin father warms his egg on his feet. A fold of skin covers it for about two months. The mother finds food at sea during this time.

Look close to the ground

Tundra plants stay low, away from strong wind. Tight clumps trap warmth. Plants grow, flower, and make seeds during the short summer. Mosses grow on soil and rocks. Antarctica has just two native kinds of flowering plant. Lichens also live on polar rocks. A lichen is a fungus sharing life with tiny algae or bacteria.

To explain an adaptation, join three ideas. For a walrus: the water is cold; it has blubber; blubber holds body heat in. Saying only "it has blubber" names the feature. Adding how it helps explains why the walrus can live there.

Arctic communities have homes, schools, stores, and families. People use warm buildings and modern travel while keeping traditions that matter to them.

Meet Arctic communities today

Inuit communities live in northern Canada, Greenland, and Alaska. Sámi people live in northern Norway, Sweden, Finland, and Russia. Many other peoples live across the Arctic too.

Most Inuit live in heated houses in towns. Some houses stand on posts. Air can pass beneath them, helping protect frozen ground from house heat. If that ground thaws, a building can sink. Thick walls help hold warmth inside.

An igloo is a snow house. Some Inuit once used snow houses as winter homes. Today they are mostly trip shelters or places built for fun. The Inuit word "iglu" means house. A snow house is only one part of Arctic life.

Get dressed for the cold

Several clothing layers trap air that holds body heat. A parka is a warm hooded coat worn over them. Hats, mittens, and warm boots cover the body's ends. Mittens keep fingers together so they share warmth. Some Inuit families still make clothing from caribou skin and sealskin. The words "parka" and "anorak" came from Arctic languages.

Find food, travel, and play

Few crops grow in the cold, short summer. Traditional foods include Arctic char, seal, whale, and caribou. Some Sámi families herd reindeer. Planes and ships bring much store food from far away. This transport helps make it expensive.

Snowmobiles, skis, and dog sleds travel over snow. Boats travel on open summer water. Many towns have no roads connecting them to other towns. Small planes carry people and supplies. Arctic peoples developed the kayak for hunting at sea.

Imagine a winter school day in Iqaluit, Nunavut. Leah puts on her parka and mittens while it is still dark. She learns English and Inuktitut at school. Later she goes sledding. Dinner might include caribou stew. In summer, long daylight gives children more time for outdoor play. Skating, skiing, and ice fishing are other cold-weather activities.

Visit an Antarctic research station

Antarctica has no permanent resident population. Scientists and helpers stay temporarily at research stations. They study ice, weather, and animals. Supplies arrive by ship or plane. McMurdo and Amundsen–Scott South Pole Station are US stations.

A desert gets very little water from rain and snow. Dryness makes it a desert. Some deserts are hot, and others are freezing cold.

Ask about the whole year

Deserts usually receive less than about 10 inches (25 centimeters) of water yearly. Snow is melted before its water is measured. A deep pile of fluffy snow contains much less water than the same depth of rain.

Phoenix, Arizona, gets about 7 inches of rain a year. It lies in the Sonoran Desert. The middle of Antarctica gets very little new snow. It is a desert too, even with all its old ice. The Amazon rainforest gets rain on most days. Its heat does not make it a desert.

Picture a hot desert day

In the Sahara, summer afternoons often pass 100 °F (about 38 °C). Few clouds shade the ground. Many hot deserts cool sharply after sunset. With few clouds, less heat is held in at night. Some winter nights approach freezing.

Deserts have more than sand. Rocky ground, gravel, mountains, and dry riverbeds are common. Sand dunes are hills of sand shaped by wind. They cover only part of the Sahara.

Find deserts across the world

The Sahara is the largest hot desert, nearly as large as the United States. Antarctica is the largest desert of all. The Gobi has hot summers and very cold winters.

Death Valley is in California's Mojave Desert. In 1913, its air temperature reached 134 °F (56.7 °C). This is the world record for the highest measured air temperature.

Look for water within the dry land

An oasis forms where underground water reaches the surface. Date palms and other plants grow there. Water helps people farm and build villages.

A river can cross a desert too. The Nile flows through the Sahara. People have farmed along its banks for thousands of years. A strip of green beside a river can sit within a very dry region.

Desert life depends on saving water and coping with heat. Some living things store supplies. Others avoid the hottest hours or find shade.

See how plants save water

A saguaro cactus stores water in its thick stem. The stem swells after rain. Its waxy skin helps keep that water inside. Spines lose little water and help keep hungry animals away. Wide, shallow roots soak up rain before it dries.

Some other plants grow long roots to reach deep water. Desert flower seeds can wait in dry soil for years. After rain, they sprout, flower, and make seeds quickly.

Watch animals use the cooler hours

Nocturnal animals are active at night. Many rest in shady burrows during the hot day. A fennec fox's large ears let body heat escape. They also help it hear insects. Fur under its feet protects them from hot sand. A kangaroo rat gets most of its water from seeds.

A camel's hump stores fat for energy, not water. Camels can go days without drinking, then drink a lot. Long eyelashes and closing nostrils help keep sand out. Wide padded feet spread their weight over soft sand.

Make shade and keep cool

Loose, long clothing shades skin and lets air move. Light colors reflect more sunlight. Head cloths can protect against sun and blowing sand. Tuareg men in the Sahara wear cloth wrapped around the head and face.

For a desert walk, take water, a wide-brimmed hat, sunglasses, and sunscreen. A loose, light-colored long-sleeved shirt shades your skin. Bring a sweater for the cooler evening. Go with an adult who knows the route and weather.

Traditional houses often have thick mud-brick or stone walls. These slow the daytime heat moving indoors. Small windows let in less hot sunlight. Some homes have flat roofs used on warm nights. Herders may use tents they can move with camels or goats.

Live in a desert community

Many people live in desert towns and cities with air conditioning. Phoenix and Las Vegas receive much water through Colorado River canals and pipes. Dubai gets most of its water by removing salt from seawater.

People grow dates, grains, and vegetables at oases and beside rivers. Herds provide milk and meat. Camels have carried travelers and goods across deserts for thousands of years. Trucks, cars, and planes carry people today too. Shade and cooler evening hours help people enjoy outdoor play and visits with friends.

Step into a tropical rainforest and you feel warm, damp air. Tall trees grow close together. Rain falls on most days, but sunshine comes between showers too.

Find warm, wet forests

Tropical rainforests grow near the equator, where low places stay hot all year. The damp, sticky air is humid. There is no cold winter.

The largest is the Amazon rainforest in South America. Most lies in Brazil around the Amazon River. The Congo rainforest in central Africa is second largest. Southeast Asia has rainforests on Borneo and Sumatra. Smaller rainforests grow in Central America and northern Australia. El Yunque grows in Puerto Rico, a US territory.

Not every rainforest is tropical. Some cool, rainy places have temperate rainforests. Washington's Olympic Peninsula and southeast Alaska have examples. A forest needs plenty of rain to be a rainforest; it does not always need tropical heat.

Travel down through four layers

Some emergent trees stand taller than a 15-story building. The canopy catches most of the sunlight. Only some light reaches the understory. Very little gets through to the floor.

Follow the light step by step

Imagine a sunbeam falling from the sky. First it reaches the tallest trees. Then the leafy canopy catches much of it. Below that roof, a plant has less light to use. Large leaves spread out to catch the dim light. A dark forest floor can lie below a bright, sunny treetop.

A forest full of useful living things

Tropical rainforests hold more kinds of plants and animals than any other land habitat. Cacao trees give us the beans used for chocolate. Bananas, rubber, and some medicines also come from tropical plants.

Trees release water into the air through their leaves. That water helps form clouds and rain. The forest helps keep its surroundings wet.

In a crowded forest, plants need ways to reach sunlight. Animals need ways to find food, move, and hide. Each layer offers different places to live.

Reach light and handle rain

Young trees grow toward gaps in the leafy roof. Vines climb trunks to reach brighter places. Air plants, including many orchids and bromeliads, grow on branches. They get water from rain and damp air.

Many leaves end in pointed drip tips. Water runs off these points after heavy rain. Tall trees often have buttress roots. These wide, flat roots spread from the trunk like low walls. They help support the tall tree.

Rainforest soil is often poor in nutrients, the materials plants need to grow. Dead leaves and fruit break down quickly in warm, wet conditions. Roots soon take up the released nutrients. Much of the forest's nutrient supply is held in living plants.

Find animals above the ground

A lot of fruit, leaves, and flowers grow in the canopy. Many animals feed there. Sloths hang from branches and eat leaves. Tiny green living things called algae grow in their fur. This green color helps them blend into leaves.

Toucans reach fruit with long bills. Spider monkeys grip branches with tails like an extra hand. Orangutans live in the canopies of Borneo and Sumatra. They do not live wild in the Amazon.

Harpy eagles nest in the tallest emergent trees. From above, they hunt animals such as sloths and monkeys. In the understory, red-eyed tree frogs grip leaves with sticky toe pads. Jaguars can rest on branches too.

Look along the forest floor

Jaguars hunt on the ground, and tapirs search for plants. In African rainforests, gorillas spend much time on the ground. Leafcutter ants carry leaf pieces to underground nests. They use those pieces to grow the fungus they eat. Insects, worms, and fungi break down fallen leaves.

To explain a match, connect the animal's food or movement to its home. Camouflage helps leaf insects and stick insects hide. Poison dart frogs use bright colors to warn hunters of poison.

Rainforests are people's homes as well as wildlife homes. Families live in villages and large cities. Their lives connect forest knowledge, modern tools, work, and traditions.

Meet forest communities

Indigenous peoples have lived in these forests for thousands of years. They know plants used for food and medicine. Yanomami communities live in Brazil and Venezuela. Mbuti communities live in the Congo rainforest. Dayak communities live on Borneo.

Many traditional homes use wood and palm-leaf roofs. Steep roofs let heavy rain run off. Open sides let breezes pass through. Some houses stand on stilts, keeping floors above damp ground and floods. Some Yanomami communities share large round houses with an open middle.

People wear light clothes in the heat. Long, light sleeves help with insect bites. Food comes from fishing, hunting, gathering, and gardens. Families grow cassava, bananas, and plantains, and gather fruits and Brazil nuts.

Travel along the rivers

Canoes and motorboats carry people where roads are few. Iquitos, in Peru, has local roads, but no road link to the country's wider road network. Travelers reach it from distant places by boat or plane.

Manaus, Brazil, is an Amazon city of about two million people. It has schools, stores, a busy port, and an opera house. Some nearby families have floating homes. Boats, phones, and city life belong in a picture of today's rainforest too. Children go to school and enjoy games with friends.

Understand why forests are cleared

People cut trees to sell wood or clear land. The land may become cattle ranches, soybean fields, or oil-palm farms. Mines and roads also replace forest. Many workers depend on these jobs to earn a living.

Clearing forest removes animal homes and feeding places. Orangutans are endangered: they face a serious danger of dying out in the wild. Forest communities can lose food, medicines, and land. Fewer trees also release less water into the air. They take less carbon dioxide from the air too.

Protect homes and livelihoods

Protected areas and national parks can keep forest standing. Laws need to be enforced to work. Planting trees helps damaged places recover. Respecting Indigenous peoples' land rights helps protect their homes. Buyers can look for products made without clearing rainforest.

In many temperate places, the year brings four seasons. Plants, animals, and people change what they do as the weather changes.

Follow trees through the year

Deciduous trees, such as oaks and maples, lose their leaves each year. Picture a maple in Ohio. New green leaves open in spring. In summer, the wide leaves give shade. In fall, leaves turn red, orange, or yellow and drop. Winter leaves bare branches, sometimes covered with snow.

Evergreen trees, such as pines and spruces, keep green leaves or needles through the year. They lose and replace some over time. They do not shed all their needles each fall like a maple loses leaves.

Find different ways through winter

Some animals leave for places with more food or warmth. Many Canada geese fly south. Monarch butterflies from the eastern United States travel to Mexico. This regular movement is migration.

Groundhogs hibernate. Their bodies cool, and heartbeat and breathing slow greatly. This saves energy until food is easier to find. Black bears spend much of winter resting in dens. Squirrels stay active and eat nuts they stored. Other animals grow thicker coats.

Change clothes, food, and fun

Spring brings planting on many farms. Summer and fall bring harvests, when crops are gathered for food. Fall leaves also make piles to rake and jump into. What you do depends on your own town's weather. Not every temperate winter has snow.

Temperate means between the hot and cold zones. Some places have large seasonal changes. Others have gentle ones. You need to know the local year to choose useful clothes.

Check the other half of Earth

Seasons are opposite across Earth's two hemispheres. When the United States and Canada have summer, Australia, New Zealand, and Argentina have winter. In Australia, Christmas falls in summer. Some families celebrate with a beach trip.

You can compare your home with a place far away. A useful comparison shows what is alike, what differs, and why.

Gather matching facts

1. Find your home on a globe or map. Check its position near the equator, between zones, or near a pole.
2. Describe its usual weather across the year. Include seasons, warmth, and rain or snow.
3. Choose one hot or cold place. Find facts about that place too.
4. Use the same headings for both: weather, land, plants, animals, homes, clothes, food, travel, and fun.

Compare one real town or area. A whole country can contain many kinds of place. Canada has Arctic towns in the north and temperate cities farther south.

Build a side-by-side comparison

Maya in Ohio compares her home with Manaus, Brazil.

Now add something shared: both places have families, schools, and stores. Children in both places play soccer. Climate changes daily life without changing people's need for friends, learning, and play.

You could also use a Venn diagram. Draw two overlapping circles. Put facts about Ohio in one outer part. Put facts about Manaus in the other. Write shared features in the middle.

Explain with a reason

"Maya needs snow boots in winter, but children in Manaus do not. Manaus is near the equator, where low places stay hot all year." This connects clothes to climate. A sentence about today's rain would not explain the whole year.

For an Arctic winter visit, layers, a parka, mittens, and boots keep warmth in. Sunglasses help with sunlight reflected from snow. Rainforest visitors need light long sleeves, rain gear, insect repellent, and boots for wet ground. Hot-desert visitors need water and sun protection, plus warmth for a cool night.

Give your own opinion

You might say, "I would like to visit Antarctica to see emperor penguins. I would find its long, dark winter hard." Your choice has reasons tied to the place. Someone else may prefer a hot rainforest or snowy town.