- Temperature varies widely in India from place to place and season to season (e.g. Barmer very hot, Kargil extremely cold).
- Coastal areas like Kerala and Andaman Islands have small temperature range, while interior and desert areas have a large range.
- Northern India experiences extreme summers and winters, whereas southern India has a more moderate climate.
- Precipitation differs in type and amount—snowfall in the Himalayas and rainfall in the rest of India.
- Rainfall distribution is uneven: very heavy in Meghalaya, very low in Rajasthan, and seasonal differences across regions.
Key Points
Key Points: Climate of India
- India lies between 8°4′N and 37°6′N, giving it both tropical and temperate climates.
- It has a tropical monsoon climate with high temperatures and seasonal rainfall.
- The Tropic of Cancer divides India into southern tropical and northern temperate zones.
- The Himalayas block cold winds, and the Indian Ocean provides moisture for monsoon rains.
- In summer, south-west monsoon winds bring heavy rain to coastal and mountain areas.
- North-east monsoon winds bring some rain to the south during the retreating monsoon.
- India's diverse geography causes regional climate differences and natural disasters like floods, droughts, and cyclones.
Key Points: Distribution of Temperature
Key Points: Factors Affecting India's Climate
- Latitude – Southern India is warmer as it lies in the tropical zone; northern India lies in the temperate zone.
- Altitude – Temperature decreases with height; hills are cooler than plains.
- Distance from Sea – Coastal areas have moderate climate; interior areas have extreme climate.
- Himalayas – Block cold winds and cause rainfall by stopping monsoon winds.
- Monsoon & El Niño – Monsoon controls rainfall; El Niño weakens monsoon, La Niña strengthens it.
Key Points: Land and Sea Breeze VS Monsoon Winds
| Land & Sea Breeze | Monsoon Winds |
|---|---|
| Local coastal winds | Regional / global winds |
| Blow daily | Blow seasonally |
| Low speed (breeze) | High speed |
| No rainfall | Heavy rainfall |
| Affect small areas | Affect large areas |
Key Points: Seasons in India > Hot Dry Summer
- Hot dry summer season lasts from March to May due to the sun’s vertical rays moving towards the Tropic of Cancer.
- High temperatures occur in interior India, while coastal and hilly areas are cooler.
- Low pressure develops over north and northwest India; seas have high pressure.
- Local winds like Loo and Kalbaisakhi blow during this season.
- Pre-monsoon showers (Mango/Blossom showers) help crops like tea, coffee, rice, and mango.
Key Points: Seasons in India > The South-West Monsoon Season
- South-West Monsoon season lasts from June to September and is the main rainy season of India.
- It is caused by differential heating of land and sea, creating low pressure over north-west India and high pressure over surrounding seas.
- South-East Trade Winds, after crossing the Equator, are deflected by the Coriolis force and blow as South-West Monsoon winds.
- These winds divide into two branches due to India’s peninsular shape: Arabian Sea branch and Bay of Bengal branch.
- The monsoon brings heavy, uneven rainfall, with orographic rain on windward slopes, while Tamil Nadu and western Rajasthan receive little rainfall.
Key Points: Seasons in India > Retreating Monsoon
- Retreating Monsoon season occurs during October and November due to the weakening of the low-pressure trough over the Ganga plains.
- The retreat of monsoon is caused by the southward movement of the sun, leading to high pressure replacing low pressure over northern India.
- Clear skies, high humidity, and high temperature cause uncomfortable weather called ‘October Heat’.
- Cyclonic depressions form over the Bay of Bengal and Andaman Sea, bringing heavy rainfall to Tamil Nadu, Odisha, and coastal Karnataka.
- Interior Deccan remains dry due to the rain-shadow effect of the Eastern Ghats, while the Coromandel Coast receives most of its rainfall.
Key Points: Seasons in India > The North-East Monsoon Season
- Cold dry winter season in India lasts from December to February due to oblique sun rays, resulting in cool weather and clear skies.
- Temperature decreases from south to north; January is the coldest month, and Drass Valley (Kashmir) is the coldest place in India.
- High pressure develops over land as it cools faster, while surrounding seas have low pressure, causing north-easterly winds.
- Western Disturbances from the Mediterranean Sea bring light rainfall and snowfall to north-western India, benefiting rabi crops like wheat and barley.
- North-East Monsoon winds, after crossing the Bay of Bengal, cause heavy rainfall on the Coromandel Coast (Tamil Nadu).
Key Points: Distribution of Rainfall
- Distribution of rainfall in India depends on pressure conditions, relief features, wind direction, and cyclonic depressions.
- Heavy rainfall regions (more than 200 cm) include the windward slopes of the Western Ghats and the Meghalaya–Assam hills.
- Moderate rainfall regions (100–200 cm) include the Middle Ganga Valley, parts of Odisha, Madhya Pradesh, Maharashtra, Andhra Pradesh, and Tamil Nadu.
- Low rainfall regions (50–100 cm) include parts of the Deccan Plateau, Punjab, Haryana, eastern Rajasthan, and Kashmir.
- Scanty rainfall regions (less than 50 cm) include the Thar Desert, Kachchh, and rain-shadow areas of the Deccan Plateau, making rainfall in India uneven and uncertain.
Key Points: From Climate to Climate Change
- Climate change means long-term changes in temperature and weather patterns, mainly caused by human activities since the Industrial Revolution.
- Burning fossil fuels (coal, oil, gas) produces greenhouse gases, especially carbon dioxide, leading to global warming.
- The Earth’s temperature has already increased by about 1.1°C, causing droughts, floods, forest fires, melting ice, rising sea levels, and storms.
- Climate change affects food security, human health, biodiversity, and water availability, and increases hunger, diseases, and forced migration.
- Everyone must take responsibility to fight climate change through long-term solutions, which need financial investment and collective action.
Key Points: Advance of the Southwest Monsoon
- Advance of the Southwest Monsoon begins with a sudden ‘burst of the monsoon’ over Kerala around 1 June, bringing relief from summer heat.
- Within one week, the monsoon covers the west coast (Kerala to Maharashtra), and by mid-July it spreads over the entire country.
- Due to the triangular shape of Peninsular India, the monsoon splits into two branches: the Arabian Sea branch and the Bay of Bengal branch.
- The Arabian Sea branch causes heavy orographic rainfall on the windward side of the Western Ghats, while the leeward (rain-shadow) areas like Pune receive very little rainfall.
- The Bay of Bengal branch brings heavy rainfall to North-East India (Mawsynram, Cherrapunji) and decreasing rainfall from east to west in the Ganga plains, finally merging with the Arabian Sea branch near the Himalayas.
Key Points: Characteristics of Southwest Monsoon
- Southwest monsoon rainfall is erratic and unreliable, so its amount and timing are uncertain.
- Rainfall is unevenly distributed across India, with some regions receiving more rain than others.
- Most of the rainfall is orographic in nature, caused by moist winds rising over mountains.
- Heavy, torrential rainfall often occurs with thunder and lightning, while western Rajasthan, Tamil Nadu, and Andhra Pradesh receive little or no rain.
- Due to India’s peninsular shape, the monsoon divides into the Arabian Sea branch and Bay of Bengal branch, and India’s economy depends heavily on its intensity.
Key Points: Differences between the Arabian Sea Branch · and the Bay of Bengal Branch of Southwest Monsoon Winds
| Arabian Sea Branch | Bay of Bengal Branch |
|---|---|
| Greater volume, more powerful | Lesser volume, less powerful |
| Heavy rain on Western Ghats | Heavy rain in North & North-East India |
| Covers larger area of India | Covers smaller area of India |
| Blows over Arabian Sea | Blows over Bay of Bengal |
| Affects west & central India | Affects north & northeast India |
Key Points: Characteristics of Retreating Southwest monsoon season
- Retreating Southwest Monsoon occurs due to the southward movement of the sun towards the Tropic of Capricorn.
- The low-pressure trough over the Northern Plains weakens, and these areas turn into high-pressure regions.
- The surrounding seas develop low pressure, helping the monsoon to withdraw.
- Clear skies, high temperature, and high humidity in October cause uncomfortable weather known as ‘October Heat’.
- Tropical cyclones form over the Bay of Bengal and Andaman Sea, bringing heavy rainfall and destruction.
Key Points: Differences between the Advancing Southwest monsoon and the Retreating Southwest Monsoon
| Advancing Southwest Monsoon | Retreating Southwest Monsoon |
|---|---|
| Progresses from south to north | Retreats from north to south |
| Makes rapid progress | Retreats gradually |
| Caused by low pressure on land | Caused by high pressure on land |
| Brings onset of rainfall | Marks withdrawal of rainfall |
| Begins around June | Occurs during October–November |
Key Points: Differences between the rainfall brought by temperate cyclones and the rainfall brought by tropical cyclones
- Temperate cyclones are milder, while tropical cyclones are stronger and more intense.
- Temperate cyclones bring less rainfall, whereas tropical cyclones cause heavy rainfall.
- Temperate cyclones are less destructive, but tropical cyclones cause greater damage to life and property.
- Rainfall from temperate cyclones is beneficial for wheat cultivation in North India.
- Rainfall from tropical cyclones often damages crops due to excessive rainfall and storms.
Key Points: Cold Dry Winter Season
- Cold dry winter season in India lasts from December to February due to oblique sun rays, causing cool weather.
- This season is marked by clear skies, low humidity, light northern winds, and low temperatures.
- Temperature decreases from south to north; January is the coldest month, and Drass Valley (Kashmir) is the coldest place in India.
- High pressure develops over land as it cools faster, while surrounding seas have low pressure.
- Western Disturbances bring light rainfall and snowfall in north-west India, while the North-East Monsoon gives heavy rainfall to Tamil Nadu and southern Andhra Pradesh.
Key Points: Characteristics of Cold dry winter season
- Cold dry winter season in India lasts from December to February due to oblique rays of the sun.
- Low temperatures in north India interiors create high pressure over land, while surrounding seas have low pressure.
- Western Disturbances from the Mediterranean Sea bring 10–15 cm of rainfall to north-western India, helping wheat and barley crops.
- North-East monsoon winds cause heavy rainfall along the Coromandel Coast (Tamil Nadu and southern Andhra Pradesh).
- The season is marked by cool weather, clear skies, light northern winds, and low humidity.
Key Points: South-West Monsoon VS Retreating Monsoon VS North-East Monsoon
| South-West Monsoon | Retreating Monsoon | North-East Monsoon |
|---|---|---|
| Blows from June to September | Blows in October–November | Blows from December to February |
| Winds blow from South-West | Winds blow from North-East | Winds blow from North-East |
| Blow from sea to land | Blow from land to sea | Blow from land to sea |
| Bring heavy rainfall to most of India | Rainfall decreases, high humidity | Rainfall only on Coromandel Coast |
| High temperature & humidity | Transition season | Cool, dry, pleasant weather |
Important Questions [39]
- Study the climate data of Station X and answer the questions that follow: a. Calculate the annual range of temperature of Station X. b. Name the rainiest month of the Station X.
- Give Two Important Characteristics of the South West Monsoon Rainfall.
- What is the Name Given to the Climate of India? Mention Any Two Factors Responsible for Such a Type of Climate.
- Give reasons for the following: The Northern Plains of India have a continental type of climate.
- Name Two Types of Cyclonic Systems that Affect India and Two Areas that Receive Rainfall from These Systems.
- Give Two Ways by Which the Trees that Are Found Here Have Adapted to the Climate.
- How Do Trees in the Tropical Desert Forests Adapt Themselves to the Dry Climate?
- Explain Two Factors that Effect of Climate of India Giving a Suitable Example for Each.
- Give a Reason for Each of the Following: the Summer Monsoon Winds Blow Over the Arabian Sea from the South West.
- Give a Reason for Each of the Following: Thar is a Desert
- Study the Climatic Data Given Below and Answer the Questions that Follow: 1) What is the Annual Range of Temperature of the Station? 2) What is the Total Annual Rainfall Experienced by the Station? 3) Why Would It Be Correct to Presume that the Station Lies in the Interior and Not on the Coast?
- Name the following: The winds that bring heavy rain to Cherrapunji.
- Name the Following: The Local Wind that Brings a Light Rainfall to South India and is Good for Tea and Coffee Crops.
- Give Geographical Reasons for Each of the Following Kanpur Has Extreme Temperature Conditions.
- Give Geographical Reasons for Each of the Following: Kochi is Warmer than Mumbai Even Though Both Lie on the Western Coast of India.
- Give Geographical Reasons for Each of the Following: the Ganga Plains Gets the Monsoon Rain Much Later than the West Coast of India.
- How is the Winter Rainfall of the Northwest Part of India Different from the Winter Rainfall of the Southeast Part of India?
- State Two Differences Between the Rainfalls that Occur from June to September and that from December to February in North India.
- Give a Geographical Reason for Each of the Following: Kerala Has the Longest Rainy Season.
- Give a Geographical Reason for Each of the Following: the Konkan Coast Experience Orographic Rainfall.
- Give a Geographical Reason for Each of the Following: the City of Kanpur in Uttar Pradesh Has a Higher Range of Temperature than that of Chennai in Tamil Nadu.
- Study the climate data given below and answer the questions that follow: Month Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec Temperature in °C 21.0 21.9 24.3 27.1 28.0 26.4 26.1 25.0 28.0
- Mention the different sources of rain in Punjab and Tamil Nadu during the winter season.
- Mention the geographical reason for the following: Patna receives heavier rain than Delhi.
- Mention the geographical reason for the following: Western Rajasthan receives no rain from the Arabian Sea branch of the South West Monsoon winds.
- Mention the geographical reason for the following: Mangalore is not cold even in the month of December.
- Study the C Limate Data Given Below and Answer the Questions that Follow: 1) Calculate the Annual Temperature Range. 2) What is the Total Annual Rainfall? 3) Presuming that the Station is Located in India, Give a Reason for Its Location Being on the East Coast Or West Coast of India.
- Give reasons for the following: When the Malabar Coast is receiving heavy rainfall in July, the Tamil Nadu coast is comparatively dry.
- Study the climate data given below and answer the questions that follow: Month Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec Temperature in °C 23.1 24.8 26.5 29.2 32 32.8 33.1 32.1 30.5 29.3 28.7
- Study the climate data of Station X and answer the questions that follow: Month Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. Temperature °C 21.0 21.9 24.3 27.2 28.0 26.4 26.1 25.4 26.0
- Mention the temperature and rainfall conditions found suitable for its growth.
- Study the climatic data of station x given below and answer the questions that follow: 1. Calculate the total annual rainfall experienced by the station. 2. What is the annual range of temperature?
- Name a State that is the First to Experience the Onset of the Monsoon.
- Give a reason for the following: Kanyakumari experiences an equable climate.
- Give a Reason for Each of the Following: Central Maharashtra Gets Less Rainfall than the Coastal Area of Maharashtra.
- Give a geographical reason for the following: Jaipur has a higher annual range of temperature than Mumbai.
- Name an Area in India Where Tropical Monsoon Forest is Found.
- There is Plenty of Rain in India During the Rainy Season, Yet We Need Irrigation. Give Two Reasons to Support this Statement.
- Give a Reason for Each of the Following: Kolkata Receives Heavier Rain than Lucknow.
Concepts [19]
- Climate of India
- Distribution of Temperature
- Factors Affecting India's Climate
- Land and Sea Breeze VS Monsoon Winds
- Seasons in India > Hot Dry Summer
- Seasons in India > The South-West Monsoon Season
- Seasons in India > Retreating Monsoon
- Seasons in India > The North-East Monsoon Season
- Distribution of Rainfall
- From Climate to Climate Change
- Advance of the Southwest Monsoon
- Characteristics of Southwest Monsoon
- Differences between the Arabian Sea Branch · and the Bay of Bengal Branch of Southwest Monsoon Winds
- Characteristics of Retreating Southwest monsoon season
- Differences between the Advancing Southwest monsoon and the Retreating Southwest Monsoon
- Differences between the rainfall brought by temperate cyclones and the rainfall brought by tropical cyclones
- Cold Dry Winter Season
- Characteristics of Cold dry winter season
- South-West Monsoon VS Retreating Monsoon VS North-East Monsoon
