Weather, Climate, and Natural Hazards

Weather vs. Climate: What's the Difference?#

People often confuse weather and climate, but they refer to very different things. Here is the key difference:

Weather is what the atmosphere is doing RIGHT NOW (or in the short term). Climate is what the weather is USUALLY like in a place over a long period of time (30+ years).

A helpful saying: "Climate is what you expect; weather is what you get!"

What Is Weather?#

Weather describes the state of the atmosphere at a specific time and place. It can change from hour to hour and day to day.

Weather includes:

• Temperature — how hot or cold the air is (°C or °F)
• Precipitation — rain, snow, sleet, or hail
• Wind — moving air; described by speed and direction
• Humidity — how much water vapor is in the air
• Cloud cover — how much of the sky is covered by clouds
• Air pressure — how much the atmosphere is pressing down (affects weather patterns)

What Is Climate?#

Climate is the average weather pattern of a region over many decades. Climate tells us what weather is typical for that place and time of year.

Examples:

• The Amazon Rainforest has a hot, wet climate (tropical climate)
• The Sahara Desert has a hot, dry climate (arid climate)
• Northern Canada has a cold, snowy climate (subarctic climate)
• England has a mild, rainy climate (temperate maritime climate)

Measuring Weather#

Scientists use special tools to measure weather:

• Thermometer — measures temperature
• Rain gauge — measures how much rain has fallen
• Barometer — measures air pressure
• Anemometer — measures wind speed
• Weather vane — shows wind direction
• Hygrometer — measures humidity

Weather stations around the world collect data that is fed into computer models to make weather forecasts.