Hinglish

Factors Determining the Climate

Class 7 Social Science · Chapter 3: Climates of India · NCERT Exploring Society: India and Beyond section 3.2

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Latitude: near the Equator the Sun's rays strike almost straight down, concentrating their heat; near the poles they slant, spread over a larger area and pass through more atmosphere. So Kanniyakumari and the Nicobar Islands are warm all year, while Srinagar is far cooler. Altitude: temperature falls as we go higher, because the air is thinner and farther from the sun-warmed ground. Ooty and Coimbatore lie at almost the same latitude, yet Ooty's summer is 10–25 °C and Coimbatore's 25–38 °C.

Nearness to the sea: the sea warms and cools slowly, so it moderates coastal temperatures. Mumbai (about 32 °C in summer, 18 °C in winter, range 14 °C) and Nagpur (up to 44 °C and down to 10 °C, range 34 °C) lie at similar latitudes, but Nagpur is far from the sea. Winds carry heat or cold and moisture: dry westerly winds from Arabia bring heat waves to Punjab and Rajasthan, and cold winds from across the Himalayas bring cold waves. Topography matters too: the Himalayas shield India from icy Central Asian winds, while the flat Thar has no such shelter.

Together these factors shape a region's climate, described over 30 years or more. A microclimate is a small area that differs from its surroundings: a shady valley, a forest, or an urban heat island, a concrete city with little greenery that traps heat and stays warmer than the countryside around it.

Explore: which factor is at work?

  1. Sort each example.

Remember

  • Latitude, altitude, nearness to the sea, winds and topography together shape climate.
  • Microclimates, like urban heat islands, differ from their surroundings.

Quick check

Mumbai and Nagpur are at similar latitudes. Why is Nagpur's temperature range much bigger?

  1. Nagpur is far from the sea
  2. Nagpur is higher in the Himalayas
  3. Mumbai is in a desert
  4. Nagpur gets no sunlight
Answer

Nagpur is far from the sea. The sea moderates coastal temperatures.

Think about it

How could a city reduce its urban heat island effect?

One answer

Plant trees and parks, keep lakes and open soil, use light-coloured roofs, and leave space for air to flow between buildings.

Practice

Practise with fresh questions at three levels (easy, medium, hard), some answered hands-on, with hints and worked answers. Get 4 of your last 5 right to finish the topic.