Onset of Monsoon
- Arabian Sea branch
- Bay of Bengal branch
- Convergence of two branches of monsoon
- Monsoon in western India
- Withdrawal of monsoon
Generally, the monsoon arrives at the southern tip of the Indian peninsula by the first week of June. Subsequently, it divides into two branches, viz. the Arabian Sea branch and the Bay of Bengal branch.
Arabian Sea Branch
The Arabian Sea branch reaches Mumbai about ten days later, i.e. around 10th of June. The Arabian Sea branch of the monsoon arrives over Surashtra-Kuchchh and central part of the country by mid-June.
Bay of Bengal Branch
The Bay of Bengal rapidly advances and reaches Assam in the first week of June. The monsoon winds are then deflected by high mountains and move towards west over the Ganga plains.
Convergence of 2 branches of monsoon
The Arabian Sea and the Bay of Bengal branches of the monsoon merge over the northwestern part of the Ganga plains.
Delhi usually receives monsoon showers from the Bay of Bengal branch by the end of June.
Monsoon in Western India
Western Uttar Pradesh, Punjab, Haryana, and eastern Rajasthan experience monsoon by the first week of July. The monsoon reaches Himachal Pradesh and the rest of the country by mid-July.
Withdrawal of Monsoon
Withdrawal or the retreat of the monsoon is a more gradual process.
- The monsoon begins to withdraw from the northwestern states of India by early September.
- The monsoon withdraws completely from the northern part of the Indian peninsular by mid-October.
- The monsoon withdraws from the rest by the country by early December.
- The islands receive the very first monsoon showers from the first week of April to the first week of May (progressively from south to north). The withdrawal of monsoon in the islands takes place from the first week of December to the first week of January.