Which one of the following causes is responsible for rainfall during winters. in north-western part of India?

1. A

   Retreating Monsoon

   (a) Retreating Monsoon. The retreating or north-east monsoon gives October–December rain mainly to the Tamil Nadu coast, not winter rain in the north-west.

2. B

   Cyclonic depression

   (b) Cyclonic depression. Bay-Bengal monsoon depressions drive summer rain in the plains; they are not the winter mechanism of Punjab–Haryana–western Uttar Pradesh.

3. C

   Western disturbances

   (c) Western disturbances. Extra-tropical cyclones born over the Mediterranean travel east in the westerlies and, in winter, bring rain and snow to north-western India and the western Himalaya. That is the official key for rabi moisture in the north-west.

4. D

   South-West Monsoon

   (d) South-West Monsoon. The June–September south-west monsoon is the summer rain system, not the winter fall of the north-west.

Summary. Official key is (c) Western disturbances. Winter rain in north-western India is frontal moisture from Mediterranean-origin disturbances. The south-west monsoon is summer rain; the retreating monsoon is mainly Tamil Nadu’s winter–northeast rain; monsoon depressions belong to the Bay in the wet season. Rabi wheat in Punjab–Haryana depends on those western disturbances.