Weather and Climate

Weather

• Weather is the state of the atmosphere over a short period of time ie a day

• Look outside and describe today’s weather. Is it sunny or cloudy? Hot or cold?

So what are examples of weather?

• Lightning • Thunder• Rain• Sunshine• Clouds

• Mist• Fog• Cool breeze• Warm breeze• Snow

Climate

• Climate is the state of the atmosphere over a long period of time, ie a year

• What do you think the climate of Australia is? How about the climate of the Arctic Cirlce?

Australia’s Climatic Regions

• In Australia we have seven climatic regions, they are:– Tropical Savannah– Tropical Maritime– Semi-arid– Warm Temperate– Mediterranean– Arid– Temperate Maritime

• You will learn more about these soon

Factors affecting climateClimate is caused by 6 main

factors:

1.Latitude

2.Altitude

3.Prevailing Wind

4.Distance from Sea

5.Ocean Currents

6.Great Mountain Barriers

LatitudeThis refers to the place’s position in relation to the Equator. Places closer to the equator are generally warmer than places closer to the poles.

The Earth rotates at an angle of 23.5º. The Sun’s rays pass through different thicknesses of atmosphere.

Note: Latitude is relevant!Longitude is irrelevant!

Near the Poles the Sun’s rays have to pass

through thicker

atmosphere, so they feel

weaker.

Near the Equator the rays pass through a

thinner layer of

atmosphere, so the sun

feels stronger there.

Altitude

Lower places (such as valleys) tend to be warmer than high places (such as

mountains and hills).

Prevailing WindsThese are the most common winds a place receives.

For example, in Winter in Perth the main winds are from the South, and these are cold (from Antarctica).

In Summer, Easterlies bring hot air off the desert.

Distance from Sea

Places on the coast have a milder (not as hot, not as cold) climate than those inland. Coastal places tend to have cooler summers and warmer winters. Compare Rottnest Island with Kalgoorlie.

Ocean Currents

These are the movements of the ocean. The temperature of the water affects the amount of rain a place has.

Warmer water tends to cause more rain. The water near the equator is warmer so these places have more rain and often cyclones.

Great Mountain Barriers

Climate can be different on either side of mountain ranges.

Places on the coastal side tend to be wetter and cooler than those on the other side. Place on the ‘dry’ side of a mountain range are said to be in a ‘rain shadow’.