Prevailing Winds - Definition, Examples, Quiz, FAQ, Trivia
Discover how wind patterns shape our weather and climate
What Are Prevailing Winds?
Prevailing winds are the winds that blow most frequently from a particular direction over a specific area of the Earth. They are like the Earth's regular breathing pattern!
Think of them as the "usual" winds for a region. For example, in the United States, the prevailing winds generally come from the west. That's why they're called the "Prevailing Westerlies."
These winds are important because they help move weather systems around the planet, bring rain to some areas, and keep other areas dry. Sailors have used prevailing winds for centuries to travel across oceans.
Wind Direction Fact
Winds are always named by the direction they come FROM. A west wind blows from west to east!
How Prevailing Winds Form
Prevailing winds form because of two main reasons:
1. Uneven Heating: The sun heats the Earth more at the equator than at the poles. Warm air rises at the equator and cold air sinks at the poles, creating giant air currents.
2. Earth's Rotation: As the Earth spins, it causes moving air to curve. This is called the Coriolis effect. In the Northern Hemisphere, winds curve to the right; in the Southern Hemisphere, they curve to the left.
Sun Heats Earth
Equator gets more direct sunlight than poles
Air Rises
Warm air rises at the equator
Air Moves
Air flows toward the poles
Earth Spins
Rotation causes winds to curve
Patterns Form
Regular wind belts create prevailing winds
Coriolis Effect
The Coriolis effect makes hurricanes spin counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere!
Global Wind Patterns
Around the world, we see three major wind belts that create the prevailing winds:
Trade Winds
Near the equator (0-30° latitude), winds blow toward the west
Westerlies
In mid-latitudes (30-60°), winds blow toward the east
Polar Easterlies
Near the poles (60-90°), winds blow toward the west
These wind patterns are important because:
• They move weather systems across continents
• They influence ocean currents
• They help distribute heat around the planet
• They affect rainfall patterns
For example, the westerlies bring most weather systems across the United States from west to east. That's why weather forecasters look to the west to see what's coming!
Prevailing Winds Quiz
Test your knowledge about prevailing winds with this quiz! Answer all 5 questions to see how much you've learned.
Frequently Asked Questions
Here are answers to some common questions about prevailing winds:
Wind Trivia
Discover some amazing facts about winds and weather!
Sailor's Secret
For centuries, sailors used the predictable trade winds to cross oceans. Christopher Columbus used them to sail to the Americas, and they're why the Caribbean is called the "West Indies."
Speed Champions
The fastest winds on Earth occur in tornadoes (over 300 mph) and in Jupiter's Great Red Spot (over 400 mph)! But the strongest regular winds are the polar easterlies that blow constantly near Antarctica.
Rain Shadow Effect
Prevailing winds create deserts! When moist air hits mountains, it drops rain on one side. The dry air then flows down the other side, creating deserts like Death Valley in California.
Wind Power
Wind turbines are placed where prevailing winds are strongest and most consistent. The best locations are hilltops, plains, and offshore where winds blow steadily from one direction.
