Southwest Monsoon
Mechanism and Agricultural Significance
The Southwest Monsoon (June–September) is the primary source of rainfall for approximately 60% of India's net sown area and accounts for ~75% of India's total annual precipitation. It originates in the Indian Ocean and Arabian Sea, driven by the differential heating between the Asian landmass and the ocean — the land heats up faster in summer, creating a low-pressure zone that draws in moisture-laden winds from the sea. The monsoon has two branches: the Arabian Sea branch (hits Kerala first, then moves into the Western Ghats and Central India) and the Bay of Bengal branch (enters through northeast India and spreads westward).
- Normal onset date over Kerala: June 1 (±7 days)
- Withdrawal from northwest Rajasthan: typically September 1, complete withdrawal by October 15
- States most dependent: Bihar, UP, Madhya Pradesh, Rajasthan, Maharashtra (kharif sowing)
- Kharif crops sown during monsoon: rice, maize, cotton, soybean, groundnut, tur (arhar)
- Agriculture's share of GDP: approximately 15–17% (2024-25)
- Approximately 50% of India's agriculture is still rain-fed (not irrigated), making LPA deviations economically significant
- Below-normal monsoon → lower reservoir storage → rabi crop irrigation also affected → food price inflation
● Tracked since April 07, 2026 · last seen June 30, 2026 · updates as the daily brief publishes