Prelims Quiz – Long Period Average and Indian Meteorological Department

Find the answers and detailed explanations at the end of the post:


Q.1. Which of the following statements most aptly describe the ‘Long Period Average’ (LPA) on the basis of which the Indian Meteorological Department brands the monsoon as ‘normal’ or ‘above/below normal’.

a. LPA is the average rainfall received by the country as a whole during the south-west monsoon, for a 50-year period.

b. LPA is the average rainfall received by the country as a whole during the north-east monsoon, for a 50-year period.

c. LPA is the average rainfall received by the country as a whole during the south-west monsoon, for a 10-year period.

d. LPA is the average rainfall received by the country as a whole during the north-east monsoon, for a 10-year period.


Q.2. Which of the following statement(s) about the Indian Meteorological Department (IMD) is/are true: (1) The Director General of Meteorology is the head of the IMD; (2) There are 10 Regional Meteorological Centres in India; (3) IMD is under the Ministry of Science and Technology.

a. Only 2

b. Only 1 and 3

c.  Only 2 and 3

d. Only 1


Q.3. The headquarters of Regional Meteorological Centres of the Indian Meteorological Department is/are located in which of the following cities: (1) Mumbai; (2) Chandipur; (3) Panaji; (4) Nagpur.

a. Only 1

b. Only 1 and 4

c. Only 1, 3 and 4

d. 1, 2, 3 and 4


Q.4. Which of the following is/are correctly paired in the context of rainfall as measured by the Indian Meteorological Department: (1) Deficit Rainfall: if actual rainfall falls below 90 per cent of Long Period Average (LPA); (2) Excessive Rainfall: if the actual rainfall is greater than 120 per cent of LPA; (3) Normal Rainfall: if actual rainfall received falls between 96 and 104 per cent of LPA.

a. Only 2 and 3

b. Only 1

c. Only 1 and 3

d. 1, 2 and 3


Q.5. Which of the following statement(s) is/are true with respect to the Long Period Average (LPA) used to determine the rainfall by the Indian Meteorological Department: (1) The current LPA is 89 cm; (2) It is based on the average rainfall over years 1951 and 2000.

a. Only 1

b. Only 2

c. Both 1 and 2

d. Neither 1 nor 2


Answers and explanation-

Q. 1 – a. LPA is the average rainfall received by the country as a whole during the south-west monsoon, for a 50-year period.

Q. 2 – d. Only 1

Q. 3 – b. Only 1 and 4

Q. 4 – c. Only 1 and 3

Q.5. – c. Both 1 and 2


LPA is the average rainfall received by the country as a whole during the south-west monsoon, for a 50-year period. The current LPA is 89 cm, based on the average rainfall over years 1951 and 2000. This acts as a benchmark against which the rainfall in any monsoon season is measured. The country is said to have received deficient rainfall if the actual rainfall falls below 90 per cent of LPA. Similarly, the country is said to have received excess rainfall if the rainfall is greater than 110 per cent of LPA. It is deemed ‘normal’ when the actual rainfall received falls between 96 and 104 per cent of LPA. Source: The Hindu Business Line.


The Director General of Meteorology is the head of the IMD. There are six Regional Meteorological Centres each under a Deputy Director General with headquarters at Mumbai, Chennai, New Delhi, Calcutta, Nagpur and Guwahati. The IMD is under the Ministry of Earth Science. Source: IMD Website.


There are six Regional Meteorological Centres of the Indian Meteorological Department each under a Deputy Director General with headquarters at Mumbai, Chennai, New Delhi, Calcutta, Nagpur and Guwahati. Source: IMD Website.


The country is said to have received deficient rainfall if the actual rainfall falls below 90 per cent of LPA. Similarly, the country is said to have received excess rainfall if the rainfall is greater than 110 per cent of LPA. It is deemed ‘normal’ when the actual rainfall received falls between 96 and 104 per cent of LPA. Source: The Hindu Business Line.


LPA is the average rainfall received by the country as a whole during the south-west monsoon, for a 50-year period. The current LPA is 89 cm, based on the average rainfall over years 1951 and 2000. Source: The Hindu Business Line.