Chapter-Chapter 3: Climates of India Social Science Part-1 class 7 in english Medium CBSE Notes

Quick Revision Notes – Climates of India

Weather, Seasons and Climate

• Weather is the day-to-day condition of the atmosphere.
• Climate is the long-term pattern of weather in a region over many years.
• Seasons occur due to the Earth's revolution around the Sun.
• India experiences six traditional seasons (Ritus).

Six Traditional Indian Seasons

• Vasanta (Spring)
• Grishma (Summer)
• Varsha (Rainy Season)
• Sharad (Autumn)
• Hemanta (Pre-Winter)
• Shishira (Winter)

Types of Climate in India

• Alpine Climate – Himalayas; snowy winters and cool summers.
• Temperate Climate – Hill stations; moderate temperatures.
• Subtropical Climate – Northern Plains; hot summers and cold winters.
• Arid Climate – Thar Desert; very hot and dry.
• Tropical Wet Climate – Western Coast; heavy rainfall.
• Semi-Arid Climate – Deccan Plateau; moderate rainfall.
• Tropical Climate – Eastern India and Southern Peninsula.

Factors Affecting Climate

1. Latitude

• Places near the Equator are hotter.
• Temperature decreases as latitude increases.
• Southern India is generally warmer than Northern India.

2. Altitude

• Temperature decreases with increasing height.
• Hill stations are cooler than nearby plains.
• Examples: Ooty, Shimla, Darjeeling, Nainital.

3. Distance from the Sea

• Sea moderates temperature.
• Coastal areas have moderate climate.
• Interior areas experience extreme temperatures.
• Mumbai is more moderate than Nagpur.

4. Winds

• Winds influence temperature and rainfall.
• Sea winds bring moisture and rain.
• Desert winds bring hot and dry conditions.

5. Topography

• Mountains, valleys, plateaus and deserts affect climate.
• Himalayas block cold winds from Central Asia.
• Western Ghats influence monsoon rainfall.

Microclimate

• A local climate different from surrounding areas.
• Found in forests, valleys and cities.
• Urban Heat Islands are examples of microclimates.

Monsoons

• Monsoon means seasonal winds.
• The word comes from Arabic word "Mausim" meaning season.
• Monsoons are very important for India's agriculture.

Southwest Monsoon (Summer Monsoon)

• Begins in early June.
• Winds blow from sea to land.
• Bring heavy rainfall across India.
• Advance from south to north.

Northeast Monsoon (Winter Monsoon)

• Winds blow from land to sea.
• Generally dry.
• Bring rainfall to Tamil Nadu and parts of southeast India.

Interesting Facts

• Mawsynram (Meghalaya) receives the highest average rainfall in the world.
• Average annual rainfall is about 11,000 mm.
• Monsoons inspire classical ragas like Meghmalhar and Amritavarshini.

Climate and Human Life

• Climate affects agriculture.
• Climate influences festivals and traditions.
• Many Indian festivals are linked with seasons and crops.
• Examples: Baisakhi, Pongal, Onam, Lohri, Bihu.

Climate and Economy

• Good monsoon supports agriculture.
• Poor monsoon causes crop failure.
• Water shortages increase during droughts.
• Food prices may rise during monsoon failure.

Climate-Related Disasters

Cyclones

• Form due to low-pressure systems over the sea.
• Bring strong winds and heavy rainfall.
• The calm centre is called the Eye of the Cyclone.

Floods

• Occur when water overflows onto land.
• Caused by heavy rainfall and river overflow.
• Common in Bihar, Assam, Kerala and Uttar Pradesh.

Landslides

• Sudden movement of rocks and soil down slopes.
• Triggered by heavy rainfall and earthquakes.
• Common in Himalayan and hilly regions.

Forest Fires

• Spread rapidly in dry conditions.
• Damage forests, wildlife and air quality.
• Often caused by drought and human carelessness.

Climate Change

• Long-term change in climate patterns.
• Mainly caused by human activities.
• Burning fossil fuels increases greenhouse gases.
• Leads to global warming.
• Causes extreme weather events.

Steps to Reduce Climate Change

• Plant more trees.
• Use renewable energy.
• Reduce greenhouse gas emissions.
• Promote sustainable lifestyles.
• Improve energy efficiency.

Important Terms

• Weather: Day-to-day atmospheric condition.
• Climate: Long-term weather pattern.
• Monsoon: Seasonal wind system.
• Topography: Physical features of an area.
• Microclimate: Localized climate of a small area.
• Cyclone: Strong rotating storm around a low-pressure centre.
• Resilience: Ability to recover from difficulties.
• Mitigation: Actions taken to reduce climate change.
• Sustainable: Able to continue for a long time without harming the environment.

Exam Booster Facts

• Weather is short-term; climate is long-term.
• Monsoon begins in India in June.
• Himalayas protect India from cold winds.
• Sea moderates coastal temperatures.
• Mawsynram receives the highest rainfall in the world.
• Eye is the calm centre of a cyclone.
• Climate change is mainly caused by human activities.
• Monsoons are the backbone of Indian agriculture.