Elements of Weather and Climate
- Temperature — degree of hotness or coldness of the atmosphere
- Humidity — amount of water vapour in the air; measured by hygrometer
- Precipitation — water falling from clouds (rain, snow, sleet, hail)
- Atmospheric pressure — weight of air pressing down; measured by barometer
- Wind — horizontal movement of air; measured by anemometer
- Cloud cover — fraction of sky covered by clouds
Factors Affecting Climate
| Factor | Effect |
|---|---|
| Latitude | Equatorial regions hotter; polar regions colder |
| Altitude | Higher altitude = lower temperature |
| Distance from sea | Coastal areas — moderate climate; interior — extreme climate |
| Ocean currents | Warm currents warm nearby coasts; cold currents cool them |
| Prevailing winds | Winds bring rain from sea or dry air from land |
| Relief | Mountains force air up, causing rainfall on windward side |
Climate Types
- Tropical Humid — hot and wet; near equator; heavy rainfall; eg. Amazon
- Tropical Dry (Desert) — hot and dry; very little rain; eg. Sahara
- Mediterranean — hot dry summers, mild wet winters; eg. southern Europe
- Temperate — moderate temperatures; four seasons; eg. Europe
- Polar / Cold — very cold; permanent ice; eg. Arctic, Antarctica
Indian Monsoon
- Meaning of Monsoon — from Arabic "Mausim" meaning season
- South-West Monsoon (June–September) — brings most of India's rainfall
- Arabian Sea branch — hits Western Ghats first, then moves inland
- Bay of Bengal branch — enters through North-East India, moves west
- North-East Monsoon (October–December) — affects Tamil Nadu coast (retreating monsoon)
- Tamil Nadu receives more rain from North-East monsoon than South-West monsoon
Seasons in India
| Season | Months | Features |
|---|---|---|
| Summer | March–May | Hot and dry; temperatures up to 45°C in north |
| Monsoon | June–September | Heavy rainfall across India |
| Retreating Monsoon | October–November | Rain over south-east India (Tamil Nadu) |
| Winter | December–February | Cool and dry; north India has snowfall |
Important Questions
One Mark
1. What instrument measures atmospheric pressure? 2. Which monsoon gives maximum rainfall to Tamil Nadu? 3. What is the meaning of the word "monsoon"? 4. Name any two elements of weather.
Three Marks
1. Explain the factors that affect the climate of a place. 2. Describe the South-West monsoon and its branches. 3. What are the four seasons in India? Describe any one.
Five Marks
1. Explain the mechanism of the Indian monsoon. 2. Compare tropical and temperate climate types with examples.
Common Mistakes
- Writing that Tamil Nadu gets maximum rain from South-West monsoon — it is the North-East monsoon
- Confusing humidity with precipitation
- Forgetting the full form of monsoon meaning (Arabic Mausim)
Revision Checklist
- Elements of weather listed with measuring instruments
- Factors affecting climate noted in table form
- Indian monsoon mechanism understood
- Tamil Nadu monsoon pattern noted correctly
- Exercise answers corrected
Frequently Asked Questions
The elements of weather include temperature, humidity, precipitation (rainfall/snowfall), wind direction and speed, cloud cover, and atmospheric pressure. These vary daily and are recorded by meteorological stations.