Look outside. Is it sunny, cloudy, windy, about to rain or snow? These conditions describe weather — something happening in a particular place at a particular time.

Climate is a pattern of weather that occurs over a long period of time — 30 years or more, or even centuries.

Different areas of the world have different climates. Climate depends on how far away you are from the equator, how near you are to the sea and how far you are above sea level.

One of the driest climates on Earth is the Atacama Desert in Chile where it has only rained a few times in the last 30 years. On those few days when it does rain, the weather is rainy, but the climate doesn't change. It's still a dry climate.

Meteorologists study weather patterns to predict the weather in the short term. They prepare us for hurricanes, tornadoes, blizzards and heat waves.

Climatologists, scientists who study climate, look at weather patterns over many years. They study the effects of climate on the land and the sea, as well as on humans, animals and plant life.

Weather can change in just a few hours, but climate takes many many years to change, even when it's changing fast like it is now.

In the last 100 years, increased carbon dioxide entering the Earth's atmosphere has caused the planet to warm up faster than it naturally would. This global warming is causing world climates to change and extreme weather and storms to occur more often.