1. Chapter at a Glance
People often say “climate” when they mean “weather”. Weather is what we feel hour by hour or day by day; climate is the long-term pattern of weather in a region over several decades (usually 30 years or more). India has a remarkable variety of climates — from icy Himalayan peaks to the hot Thar and the rain-soaked west coast. This chapter explains seasons and ṛitus, India's climate types, the factors that control climate, the monsoons, how climate shapes our economy and culture, climate-related disasters and climate change.
- Weather, seasons and climate; the six traditional ṛitus.
- Climate types of India.
- Factors: latitude, altitude, nearness to the sea, winds, topography; microclimates.
- How the south-west and north-east monsoons work.
- Cyclones, floods, landslides, forest fires; climate change and what we can do.
2. Weather, Seasons and Climate
Seasons recur every year as the Earth revolves around the Sun, and the weather differs in each. Much of the world has four seasons, but India also has a distinct rainy season. Traditionally the Indian year has six ṛitus:
| Ṛitu | Season | Associated festival (example) |
|---|---|---|
| Vasanta | Spring | Vasanta Pañchamī |
| Grīṣhma | Summer | — |
| Varṣhā | Rainy season | — |
| Śharad | Autumn | Śharad Pūrṇimā |
| Hemanta | Pre-winter | — |
| Śhiśhir | Winter | — |
Plants, animals and people live in rhythm with seasons — crops, food, clothes, flowering and leaf-fall change with them. Climate usually stays stable for long periods, but scientists now record changes, many caused by human actions.
3. Climates of India
| Region | Climate | Features |
|---|---|---|
| High Himalayas | Alpine | Cold, snowy winters; cool summers |
| Lower Himalayas and hills | Temperate | Moderate winters and summers; hill stations |
| Northern Plains | Subtropical | Very hot summers, cold winters; most of India's wheat |
| Thar Desert | Arid | Very hot days, cool nights, very little rain |
| West coast | Tropical wet | Heavy monsoon rain; rice and spices |
| Deccan Plateau | Semi-arid | Hot summers, mild winters, moderate rain |
| East India and southern peninsula | Tropical | Mild winters; distinct wet and dry seasons |
4. Factors Determining Climate
- Latitude: near the Equator the Sun's rays fall almost vertically, concentrating heat; towards the poles they fall slantingly, spread over a larger area and pass through more atmosphere. So Kanniyakumari and the Nicobar Islands are warm all year while Srinagar is cooler.
- Altitude: temperature falls with height because air becomes thinner and is farther from the Sun-heated ground. Hill stations — Ooty, Munnar, Shimla, Darjeeling, Shillong, Tawang — are cool. Ooty (10–25°C in summer) is far cooler than nearby Coimbatore (25–38°C) at almost the same latitude.
- Nearness to the sea: water heats and cools slowly, so the sea moderates coastal temperatures. Mumbai (about 32°C in summer, 18°C in winter; range ~14°C) is milder than inland Nagpur (up to 44°C and ~10°C; range ~34°C) at a similar latitude. Inland places have a continental (extreme) climate.
- Winds: hot dry winds from Arabian and Afghan deserts cause summer heat waves in Punjab, Haryana, Rajasthan and Madhya Pradesh; cold winds from beyond the Himalayas cause winter cold waves. Winds from the sea bring moisture and rain.
- Topography: the Himalayas and Karakoram shield India from icy Central Asian winds; the flat Thar has no barrier against hot winds; the Western Ghats force monsoon winds to rise and shed rain.
A microclimate is the special climate of a small area — a closed valley, a forest, or an urban heat island, where concrete and few trees make a city much hotter than its surroundings.
5. The Monsoons
Monsoon comes from the Arabic mausim, “season”. It refers to seasonal winds that reverse direction between summer and winter over the Indian Ocean region. The key fact: land heats and cools faster than the sea.
- Summer (south-west monsoon): the Asian land heats up and forms a strong low-pressure area. Cooler, high-pressure air over the ocean flows towards the land, carrying moisture that falls as heavy rain. The rains reach India's southern tip in early June and cover the whole country by about mid-July. The western slopes of the Western Ghats get heavy rain; the Deccan to their east gets less (rain-shadow).
- Winter (north-east monsoon): the land cools faster and has high pressure; dry winds blow from land to sea. Winds crossing the Bay of Bengal pick up moisture and bring winter rain to parts of east and south India, especially Tamil Nadu.
Mawsynram (Meghalaya) gets the highest average annual rainfall in the world, about 11,000 mm. The monsoon has inspired rāgas such as Megh Malhār and Amṛitavarṣhiṇī. Traditional signs of its arrival include fish rising to the surface on the Konkan coast, the blossoming of the Golden Shower tree (Cassia fistula) and the height of crows' nests.
6. Climate and Our Lives
Many festivals follow seasons and harvests — Bihu, Pongal, Makar Sankranti, Lohri, Baisakhi, Onam, Gudi Padwa, Chhath, Losoong and Hemis. A “monsoon failure” (poor rain) damages crops, forces women to walk farther for water, pushes labourers to migrate to cities, and raises food prices (inflation). Industry also depends on predictable weather and water.
7. Climate-related Disasters
- Cyclones: an intense low-pressure system over warm sea draws in moist winds that spiral inward with high speed and heavy rain; the calm cloudless centre is the eye. India's east coast is hit most often. The IMD tracks cyclones; the National Disaster Response Force (NDRF), with battalions at 12 locations, carries out rescue.
- Floods: water overflows onto normally dry land due to heavy rain or overflowing rivers and lakes. Uttar Pradesh, Bihar, Assam, Kerala and Andhra Pradesh are flood-prone. In the Himalayas, a glacial lake outburst occurs when water bursts through its barrier of rock and ice; the 2013 Uttarakhand disaster near Kedarnath killed about 6,000 people. Cities flood when drains are overloaded, waterways are built over and concrete stops water soaking in.
- Landslides: sudden collapse of rock and soil, common in Himachal Pradesh, Uttarakhand, Sikkim, Arunachal Pradesh and the Western Ghats during monsoons; worsened by deforestation and unplanned construction.
- Forest fires: spread in dry, hot, windy conditions and through human carelessness — Uttarakhand, Himachal Pradesh, Madhya Pradesh, Chhattisgarh, Western Ghats; they destroy forests and wildlife and pollute the air.
8. Climate Change
Climate change is a long-term shift in temperature, rainfall and weather events. In the past it had natural causes, but since the 19th century it has been driven mainly by human activity — burning fossil fuels (coal, oil, natural gas), deforestation, polluting industries and wasteful consumption. Gases such as CO₂ naturally trap some heat (the greenhouse effect) and keep Earth warm enough for life; adding huge amounts very quickly traps extra heat, causing global warming. In early 2025, India's average temperature was 1–3°C above normal and winter was shorter and milder — affecting crops and small industries. We can help by saving energy, using public transport, planting trees, reducing waste and protecting forests and water.
9. Master Table: Key Terms
| Term | Meaning |
|---|---|
| Climate | Long-term (30+ years) weather pattern of a region |
| Ṛitu | One of six traditional Indian seasons |
| Topography | Physical surface features of an area |
| Microclimate | Special climate of a small area |
| Urban heat island | City much warmer than its surroundings |
| Monsoon | Seasonal reversing winds; from Arabic mausim |
| Cyclone / eye | Violent spiralling storm / its calm centre |
| Fossil fuels | Coal, oil, gas formed from ancient life |
| Greenhouse effect | Trapping of heat by gases such as CO₂ |
10. Master Summary Table
| Feature | South-west monsoon | North-east monsoon |
|---|---|---|
| Season | Summer (June–September) | Winter (October–December) |
| Pressure | Low over land | High over land |
| Wind direction | Sea → land | Land → sea |
| Rain | Most of India | Parts of east and south India, esp. Tamil Nadu |
Chart — annual temperature range (°C, approximate):
11. Mind Map
- Weather vs climate
- Six ṛitus
- Latitude, altitude, sea
- Winds, topography
- SW summer, NE winter
- Mawsynram
- Cyclones, floods
- Landslides, fires
- Fossil fuels
- Global warming
12. Tips and Tricks
- Climate factors: “LASWT” — Latitude, Altitude, Sea, Winds, Topography.
- Monsoon key: land heats fast → low pressure → wind comes from the sea.
- Six ṛitus in order: “Very Good Village Schools Help Students” — Vasanta, Grīṣhma, Varṣhā, Śharad, Hemanta, Śhiśhir.
- Naming monsoons by where they go — they are named by where the winds come from.
- Saying the greenhouse effect is entirely harmful — the natural effect supports life.
13. Important One-liners
- Climate is the weather pattern over 30 years or more.
- India traditionally has six ṛitus.
- Temperature falls as altitude increases.
- The sea moderates coastal temperatures.
- “Monsoon” comes from the Arabic word mausim.
- The south-west monsoon reaches Kerala in early June.
- The north-east monsoon brings winter rain to Tamil Nadu.
- Mawsynram gets about 11,000 mm of rain a year.
- The eye of a cyclone is calm.
- The NDRF responds to disasters.
14. Exam-pattern Questions with Detailed Answers
Which place receives the highest average annual rainfall in the world?
- Cherrapunji
- Mawsynram
- Mumbai
- Kochi
Show answer
Mawsynram in Meghalaya, about 11,000 mm a year.
Answer: (B)
Differentiate between weather and climate.
Show answer
Weather is the day-to-day state of the atmosphere; climate is the average pattern of weather over 30 years or more.
Answer: Short-term vs long-term
What type of climate does the Thar Desert have?
Show answer
Arid — very hot days, cool nights, very little rain.
Answer: Arid
Ooty and Coimbatore are at almost the same latitude, yet Ooty is much cooler. Why?
Show answer
Ooty lies at a much higher altitude in the Nilgiris. Temperature falls with height because air is thinner and farther from the Sun-heated ground.
Answer: Higher altitude
Why does Mumbai have a smaller temperature range than Nagpur?
Show answer
Mumbai is on the coast; the sea heats and cools slowly, keeping summers cooler and winters warmer (range ~14°C). Nagpur is inland, so it has extreme temperatures (range ~34°C).
Answer: Moderating effect of the sea
Explain how the south-west monsoon is formed.
Show answer
In summer, the land heats faster than the sea and forms a low-pressure area. Moist winds from the high-pressure ocean blow towards the land from the south-west, rise, cool and drop heavy rain.
Answer: Low pressure over hot land draws moist sea winds
What is an urban heat island? Suggest two ways to reduce it.
Show answer
A city much warmer than its surroundings because concrete and asphalt absorb heat and there is little greenery. Remedies: plant trees and parks, use light-coloured roofs, create water bodies and green roofs.
Answer: Hot city microclimate; more greenery, cool roofs
Explain the effects of a monsoon failure on India's economy and society.
Show answer
Crops fail and farm incomes fall; drinking water becomes scarce and women walk farther for water; labourers migrate to cities; food prices rise (inflation); water-dependent industries and hydropower suffer.
Answer: Crop loss, water scarcity, migration, inflation, industrial losses
Identify natural and human causes of floods and landslides, and suggest preventive measures.
Show answer
Natural: very heavy rain, cloudbursts, glacial lake bursts, earthquakes. Human: deforestation, building on river beds and slopes, blocked drains, concrete surfaces. Prevention: plant trees, follow safe building rules, keep drains and waterways clear, early-warning systems, rainwater harvesting.
Answer: Both causes; reforestation, planning and warnings
How does burning fossil fuels cause climate change?
Show answer
Burning coal, oil and gas releases large amounts of CO₂ and other greenhouse gases very quickly. These trap extra heat in the atmosphere, strengthening the greenhouse effect and warming the planet — changing rainfall patterns and increasing extreme events.
Answer: Extra greenhouse gases trap more heat
Why does the Deccan Plateau get less monsoon rain than the west coast?
Show answer
Moist south-west winds rise over the Western Ghats and shed most of their rain on the western (windward) slopes. By the time they cross to the east, they are drier, so the Deccan lies in a rain-shadow and gets less, irregular rain.
Answer: Rain-shadow of the Western Ghats
15. Quick Revision Summary
- Weather is short-term; climate is the 30+ year pattern; India has six ṛitus.
- Climate types: alpine, temperate, subtropical, arid, tropical wet, semi-arid, tropical.
- Factors: latitude, altitude, sea, winds, topography; microclimates and urban heat islands.
- Monsoons reverse seasonally: SW in summer, NE in winter; Mawsynram wettest.
- Disasters — cyclones, floods, landslides, forest fires; climate change from fossil fuels.