Monsoon (Geography)
Monsoon (Geography)
Why In News:
The India Meteorological Department (IMD) announced on 9 July 2026 that the southwest monsoon had advanced into the remaining parts of Rajasthan, Haryana and Punjab, completing its coverage of the entire country, a day later than the normal date of 8 July.
Source: The Hindu, Page 1, 10 July 2026 - 'Monsoon has covered the entire country, a day later than normal, announces IMD'
Monsoon Onset and Advance
The southwest monsoon typically sets in over Kerala around 1 June and progressively covers the entire country by 8 July.
IMD's Forecasting Tools and Regional Variation
Monsoon Mission Climate Forecast System (MMCFS): IMD's dynamical model used for seasonal forecasting.
Long Period Average (LPA): the benchmark average rainfall over a fixed reference period, used to classify seasonal rainfall as surplus, normal, deficient or scanty.
Weak El Nino conditions were reported over the equatorial Pacific and are likely to strengthen during the season; El Nino years are typically, though not always, associated with below-average monsoon rainfall in India.
Significance for India
The southwest monsoon contributes nearly 70-75% of India's annual rainfall and is critical for kharif sowing, reservoir levels, hydropower generation and rural incomes.
Close to half of India's net sown area remains rain-fed rather than irrigated, making the monsoon central to agricultural output and food inflation.
Key Facts for Prelims
IMD is headquartered in New Delhi and functions under the Ministry of Earth Sciences.
The monsoon cycle has distinct stages:
Onset over Kerala: Marks the official beginning of the monsoon as moist southwesterly winds bring the first widespread rains to the southwestern coast.
Advance across the country: The monsoon gradually spreads northward and eastward, covering most parts of India within a few weeks.
Active/Break spells: Periods of intense rainfall (active phase) alternate with weaker rainfall or dry conditions (break phase).
Withdrawal: The monsoon retreats in reverse order, starting from northwest India around mid-September and moving southward.
The northeast (retreating) monsoon subsequently brings rainfall to Tamil Nadu, coastal Andhra Pradesh and parts of Kerala and Karnataka between October and December.