Imagine boarding a plane at the frozen edge of the Arctic and flying straight south to the steaming equator. Outside your window the world shifts from white ice, to green forests, to golden deserts, to dripping rainforest — all because of where the Sun's rays strike hardest.
Why latitude is the biggest control
Latitude is how far north or south of the equator you are. Near the equator the Sun is high overhead, so its energy hits a small area of ground and heats it strongly. Near the poles the same rays strike at a low, slanting angle, spreading over a wider area and passing through more atmosphere, so they warm the ground far less.
Other controls on climate
- Altitude — the higher you climb, the colder it gets (about 1 degree C cooler for every 100 m). Mountain tops can be snowy even near the equator.
- Distance from the sea — the sea heats and cools slowly, so coasts have milder, more even temperatures; inland places get hotter summers and colder winters.
- Ocean currents — warm currents like the North Atlantic Drift carry heat towards north-west Europe, keeping Britain milder than its latitude alone would suggest.
- Prevailing winds — the usual wind direction can bring damp air from the sea or dry air from the land, adding to a region's character.
All these controls act together. A place high in the mountains, far inland, at a high latitude will be cold indeed; a low, coastal spot near the equator warmed by a friendly current will be hot and steady. Geographers weigh up every factor when they explain why one country feels so different from its neighbour.
The main climate zones
| Zone | Rough latitude | Typical climate |
|---|---|---|
| Polar | Near 66 to 90 degrees | Freezing, dry, long dark winters |
| Temperate | About 40 to 60 degrees | Mild, four seasons, changeable |
| Arid / desert | Around 20 to 30 degrees | Very hot days, cold nights, little rain |
| Tropical | Near the equator | Hot and wet all year |