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Question
Describe the climatic conditions which prevail over India during different Seasons.
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Solution
- The Cold Season: The cold Season lasts from December to February.
(a) Temperature: The sun is over head at Tropic of Capricorn. India has winter Season. January is the coldest month. The Southern parts have warm conditions (20°C) while low temperatures (10°C) are found in North-West India.
(b) Pressure and Winds: High pressure is developed over N.W. part while a low pressure exists over Indian Ocean with the result winds blow from land to Sea. The out-blowing winds are Westerly in Northern plain and North Easterly over the rest of the country.
(c) Rainfall: The North-east Monsoons are off-shore wind and are dry but these winds pick up some moisture while crossing Bay of Bengal and give rain to South-east coast of India. Some cyclones from Mediterranean Sea also bring a small amount of rain (10 to 20 cm.) to Northern plains. Night frost is common in the North-west parts. - The Hot Season: The hot Season lasts from March to May.
(a) Temperature: As the sun’s rays fall vertical over Tropic of Cancer, the temperature begins to rise. The average temperature is above 30°C, the maximum temperature rises to 50°C in Barmer (Rajasthan). The daily range of temperature rises in inland areas.
(b) Pressure and Winds: Intense heat results in the development of low pressure over North-West India. A high pressure exists over Indian Ocean. South-West Monsoons begin to blow from Sea to land. ‘Nor-westers’ and ‘Loo’ blow over Northern plains.
(c) Rainfall: Some areas receive convectional rainfall. The west coast also starts receiving rainfall. Most of the country is dry in title pre-Monsoon period. - The Rainy Season: The rainy Season lasts from June to September.
(a) Temperature: The sun shines vertical over Tropic of Cancer. The temperatures are more than 30°C. With the onset of monsoon there is a drop in temperature (5°C to 10°C) with the result, July is not the hottest month.
(b) Pressure and Winds: South-West Monsoons blow from Sea to land with a ‘burst’ on the West Coast. It blows in two currents.
(I) The Arabian Sea Current (II) The Bay of Bengal Current.
(c) Rainfall: Most of the parts of India receive rainfall in this Season. The Arabian Sea branch gives heavy rainfall on the west coast, but Deccan plateau lies in rain shadow of western Ghats. The Bay of Bengal branch gives heavy rainfall in Eastern Himalayas. The rainfall goes on decreasing up the Ganges Valley with the decrease in moisture. Rajasthan is practically a desert.
RELATED QUESTIONS
How is the winter rainfall of the northwest part of India different from the winter rainfall of the southeast part of India?
There is plenty of rain in India during the rainy season, yet we need irrigation. Give two reasons to support this statement.
Give geographical reasons for each of the following:
Kochi is warmer than Mumbai even though both lie on the western coast of India.
Mention the geographical reasons 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.
| Stations | Latitude | Altitude (Metres) | Jan. | Feb. | Mar. | Apr. | May. | Jun. | July. | Aug. | Sep. | Oct. | Nov. | Dec. | Annual Rainfall |
|
Temperature (°C) |
20.5 |
22.7 |
25.2 |
27.1 |
26.7 |
24.2 |
23.0 |
23.0 |
23.1 |
22.9 |
18.9 |
20.2 |
|||
| Bengaluru | 12°58'N | 909 |
|
|
|
||||||||||
| Rainfall (cm) | 0.7 | 0.9 | 1.1 | 4.5 | 10.7 | 7.1 | 11.1 | 13.7 | 16.4 |
15.3 |
6.1 |
1.3 |
88.9 | ||
|
Temperature (°C) |
24.4 |
24.4 |
26.7 |
28.3 |
30.0 |
28.9 |
27.2 |
27.2 |
27.2 |
27.8 |
27.2 |
25.0 |
|||
|
Mumbai |
19° N | 11 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Rainfall (cm) |
0.2 |
0.2 |
– |
– |
1.8 |
50.6 |
61.0 |
36.9 |
26.9 |
4.8 |
1.0 |
– |
183.4 | ||
|
Temperature (°C) |
19.6 |
22.0 |
27.1 |
30.1 |
30.4 |
29.9 |
28.9 |
28.7 |
28.9 |
27.6 |
23.4 |
19.7 |
|||
|
Kolkata |
22°34'N | 6 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Rainfall (cm) |
1.2 |
2.8 |
3.4 |
5.1 |
13.4 |
29.0 |
33.1 |
33.4 |
25.3 |
12.7 |
2.7 |
0.4 |
162.5 | ||
|
Temperature (°C) |
14.4 |
16.7 |
23.3 |
30.0 |
33.3 |
33.3 |
30.0 |
29.4 |
28.9 |
25.6 |
19.4 |
15.6 |
|||
|
Delhi |
29° N | 219 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Rainfall (cm) |
2.5 |
1.5 |
1.3 |
1.0 |
1.8 |
7.4 |
19.3 |
17.8 |
11.9 |
1.3 |
0.2 |
1.0 |
67.0 | ||
|
Temperature (°C) |
16.8 |
19.2 |
26.6 |
29.8 |
33.3 |
33.9 |
31.3 |
29.0 |
20.1 |
27.0 |
20.1 |
14.9 |
|||
|
Jodhpur |
26°18'N | 224 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Rainfall (cm) |
0.5 |
0.6 |
0.3 |
0.3 |
1.0 |
3.1 |
10.8 |
13.1 |
5.7 |
5.7 |
0.2 |
0.2 |
36.6 | ||
|
Temperature (°C) |
24.5 |
25.7 |
27.7 |
30.4 |
33.0 |
32..5 |
31.0 |
30.2 |
29.8 |
28.0 |
25.9 |
24.9 |
|||
|
Chennai |
13°4'N | 7 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Rainfall (cm) |
4.6 |
1.3 |
1.3 |
1.8 |
3.8 |
22.2 |
8.7 |
11.3 |
11.9 |
30.6 |
35.0 |
0.2 |
128.6 | ||
|
Temperature (°C) |
21.5 |
23.9 |
28.3 |
32.7 |
35.5 |
32.0 |
27.7 |
27.3 |
27.9 |
26.7 |
23.1 |
20.7 |
|||
|
Nagpur |
21°9'N | 312 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Rainfall (cm) |
1.1 |
2.3 |
1.7 |
1.6 |
2.1 |
22.2 |
37.6 |
28.6 |
18.5 |
5.5 |
2.0 |
13.9 |
124.2 | ||
|
Temperature (°C) |
9.8 |
11.3 |
15.9 |
18.5 |
19.2 |
20.5 |
21.1 |
20.9 |
20.9 |
17.2 |
13.3 |
10.4 |
|||
|
Shillong |
24°34'N | 1461 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Rainfall (cm) |
1.4 |
2.9 |
5.6 |
14.6 |
29.5 |
47.6 |
35.9 |
34.3 |
30.2 |
18.8 |
3.8 |
1.0 |
225.3 | ||
|
Temperature (°C) |
26.7 |
27.3 |
28.3 |
28.7 |
28.6 |
26.6 |
26.2 |
26.2 |
26.5 |
26.7 |
26.6 |
26.5 |
|||
|
Thiruvananthapuram |
8°29'N | 61 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Rainfall (cm) |
2.3 |
2.1 |
3.7 |
10.6 |
20.8 |
35.6 |
22.3 |
14.6 |
13.8 |
27.3 |
20.6 |
7.5 |
181.2 | ||
|
Temperature (°C) |
−8.5 |
−7.2 |
−0.6 |
6.1 |
10.0 |
14.4 |
17.2 |
16.1 |
12.2 |
6.1 |
0.0 |
−5.6 |
|||
|
Leh |
34°N | 3506 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Rainfall (cm) |
1.0 |
0.8 |
0.8 |
0.5 |
0.5 |
0.5 |
1.3 |
1.3 |
0.8 |
0.5 |
– |
0.5 |
8.5 |
In above Table the average mean monthly temperatures and amounts of rainfall of ten representative stations have been given. It is for you to study on your own and convert them into ‘temperature and rainfall’ graphs. A glance at these visual representations will help you to grasp instantly the similarities and differences between them. One such graph (Figure 1) is already prepared for you. See if you can arrive at some broad generalisations about our diverse climatic conditions. 
Give an account of the distribution of annual rainfall in India.
What is meant by a ‘Rain Shadow’ area?
Study the table given below and answer the questions that follows:
| Station | Months | J | F | M | A | M | J | J | A | S | O | N | D |
| A | Temperature in °C | 12.7 | 15.1 | 22.1 | 31.8 | 37.2 | 39.1 | 37.3 | 33.4 | 28 | 26.7 | 16.1 | 13.6 |
| Rainfall in cms | 2.1 | 2.3 | 1.0 | 0.9 | 1.5 | 5.6 | 18.3 | 18.9 | 15.1 | 0.6 | 0.3 | 1.8 | |
| B | Temperature in °C | 23.1 | 24.8 | 26.5 | 29.3 | 32 | 32.8 | 33.1 | 32.1 | 30.5 | 29.3 | 28.7 | 26.1 |
| Rainfall in cms | 15.3 | 10.1 | 0.3 | 0.1 | 1.3 | 4.5 | 6.1 | 10.2 | 10.5 | 20.1 | 16.8 | 19.0 |
(a) Calculate the annual rainfall in station A.
(b) What is the annual range of temperature in station B?
(c) Name the winds that bring most of the rainfall to station B. State one reason for your answer.
What is the source of winter rainfall in Tamil Nadu?
