CG Board Class 9 Social Science Chapter 3 Solutions: India’s Climate (भारत की जलवायु) – 2026-27

In India and Chhattisgarh, we receive the highest rainfall during the months of July and August. This is because the moisture-laden South-West Monsoon winds from the Arabian Sea and Bay of Bengal reach their peak strength across the subcontinent during these months.

When it rains, the extreme atmospheric heat decreases and the weather turns cool. Dry trees, plants, and grasslands bloom with lush greenery, ponds and rivers fill with water, and agricultural fields are prepared for paddy sowing.

Based on textbook page 67:

1. Average Daily Temperature:

Average Daily Temperature = (Maximum Temperature of the Day + Minimum Temperature of the Day)/(2)

1. Average Monthly Temperature:

Average Monthly Temperature = (Sum of Average Daily Temperatures in the Month)/(Number of Days in that Month (30 or 31))

1. Average Annual Temperature:

Average Annual Temperature = (Sum of Average Monthly Temperatures of all 12 Months)/(12)

According to the textbook temperature statistics for Delhi, January is the coldest month and May/June is the hottest month.

Coastal cities like Mumbai and Chennai have an even or less variable climate because sea breezes regulate and moderate their temperatures throughout the year.

• English Step-by-Step Calculation:
• Formula: Average Annual Temperature = (Sum of 12 Monthly Average Temperatures)/(12)
• By adding the 12 monthly average temperatures of Jagdalpur from the table and dividing the total sum by 12, we get the average annual temperature of Jagdalpur as approximately 24°C to 25°C.
• हिंदी चरण-दर-चरण गणना:
• सूत्र: वार्षिक औसत तापमान = (12 महीनों के औसत तापमानों का योग)/(12)
• तालिका से जगदलपुर के 12 महीनों के मासिक औसत तापमानों का योग करके कुल योग को 12 से विभाजित करने पर, जगदलपुर का औसत वार्षिक तापमान लगभग 24°C से 25°C प्राप्त होता है।

Leh (and Shimla) situated at high altitudes in the mountain ranges has the lowest average temperature among the listed cities.

1. Mumbai: Situated on the sea coast, Mumbai experiences an equitable/maritime climate with very small differences between summer and winter temperatures.
2. Jagdalpur: Located in the interior plateau region, Jagdalpur experiences moderate thermal variation with distinct summer heat and cooler winter months compared to Mumbai.

Climate:** Climate refers to the sum total of atmospheric conditions (temperature, rainfall, pressure, wind, humidity) over a large area taken over a long duration of time (more than 30 years).

• Difference: Weather describes short-term atmospheric conditions at a specific place over minutes, hours, or days (e.g., sunny morning, rainy afternoon). In contrast, climate represents the long-term stable pattern and cycle of weather over decades.

The main elements associated with both weather and climate are:

1. Atmospheric Temperature
2. Air Pressure
3. Wind Direction and Speed
4. Humidity
5. Cloud Cover
6. Rainfall / Precipitation

Reasons for Weather Changes:** Weather changes constantly due to rapid changes in local air temperature, pressure differences, shifts in wind direction, humidity levels, and movement of cloud systems.

• Personal Experience: In Chhattisgarh, we experience a hot and dry morning during summer, followed by sudden evening dust storms or rain showers. In monsoon, a bright clear morning can quickly turn into heavy torrential rainfall by afternoon due to shifting cloud currents.

During the South-West Monsoon season, countries in the South Asian subcontinent receive heavy rainfall, including India, Bangladesh, Nepal, Bhutan, Myanmar, Pakistan, and Sri Lanka.

1. Agriculture: Temperature and rainfall dictate crop cycles, sowing schedules, and crop selection (e.g., paddy requires high rainfall and heat, while wheat grows in cooler winter temperatures).
2. Livelihood & Economy: Timely monsoon rainfall ensures strong agricultural production and water availability in reservoirs.
3. Human Life & Clothing: Extreme heat waves (loo) or intense cold waves cause severe health risks, while seasonal temperatures determine our food habits, housing styles, and clothing choices.

India has 4 main seasons:

1. Summer (March to May): High temperatures, hot dry winds (loo) blow in plains. Activities: People use fans/coolers, harvest rabi crops, and schools have summer vacations.
2. Rainy/Monsoon Season (June to September): Heavy moisture-laden winds bring rainfall across India. Activities: Farmers plow fields and transplant paddy; rivers and reservoirs fill up.
3. Autumn / Retreating Monsoon (October to November): Skies clear up, temperature drops, and cyclones affect eastern coasts. Activities: Farmers harvest kharif crops and celebrate major festivals like Diwali and Dussehra.
4. Winter (December to February): Low temperatures, chilly winds, and fog in northern plains. Activities: Farmers sow rabi crops like wheat and pulses; people wear woollens and sit around fires.

Arrival of Monsoon (Onset):** In May-June, intense heating creates a strong low-pressure belt over north-western India. This draws moisture-laden South-East Trade winds from the southern Indian Ocean. As these winds cross the Equator, they deflect right (due to Ferrel’s Law) and strike Kerala as the South-West Monsoon on June 1st, advancing into Chhattisgarh by June 15th.

• Departure of Monsoon (Retreat): In October-November, as the sun shifts southwards, the low-pressure belt weakens over North India and moves to the Bay of Bengal. Monsoon winds retreat from North India towards the sea, giving rise to cyclonic rainfall on the Coromandel Coast (Tamil Nadu).

1. No Relief Rainfall: Mountain barriers like the Himalayas and Western Ghats force moisture-laden monsoon winds to rise and condense into rain. If there were no mountains, monsoon winds would sweep across India without causing heavy rainfall, making the subcontinent dry and arid.
2. No Protection from Freezing Winds: The Himalayas block cold icy winds blowing from Central Asia and Northern Arctic regions during winter. Without mountains, North India would suffer freezing winters.
3. Uniform Solar Radiation: On a completely flat Earth, solar rays would strike at equal angles everywhere, eliminating latitudinal temperature variations.

(a) Summer all year round:** Rivers and water sources would dry up, crops would scorch, drought conditions would prevail, and agricultural production would collapse.

• (b) Rains all year round: Severe waterlogging, permanent floods, crop damage due to excessive moisture, outbreak of epidemics, and damp weather conditions would disrupt human life.
• (c) Autumn all year round: Pleasant moderate temperatures would prevail, but lack of distinct seasonal temperature changes would hamper balanced agricultural crop rotation.
• (d) Winter all year round: Continuous freezing conditions would prevent seed germination for tropical crops (like paddy), ice cover would shrink farmland, and human economic activities would slow down severely.