Monsoon retreats from northwest India as temperatures rise, while a strengthening Bay of Bengal system threatens heavy rain across several states.
Low-pressure system over the Bay may intensify further, bringing heavy rainfall and strong winds to Odisha, Andhra Pradesh and neighbouring regions.
Delhi-NCR is expected to remain mostly dry, with temperatures nearing 36°C as monsoon withdrawal brings warmer daytime conditions.
Heavy rainfall warnings cover Karnataka, Telangana, Tamil Nadu, Chhattisgarh, Maharashtra and other regions amid thunderstorms, lightning and gusty winds.
Fishermen face dangerous sea conditions as strong winds are forecast across the Bay of Bengal, Arabian Sea and surrounding coastal waters.
India is witnessing a contrasting weather pattern as the southwest monsoon begins its withdrawal from parts of northwest India, while a strengthening low-pressure system over the Bay of Bengal threatens to bring heavy rain, strong winds and thunderstorms to several states.
According to the weather outlook issued on September 21, conditions are becoming favourable for the further withdrawal of the monsoon from parts of Rajasthan, Punjab and Saurashtra-Kutch over the next two to three days. The retreat is expected to bring drier conditions to parts of northern India, including Delhi-NCR, where daytime temperatures are likely to rise.
The shift has already been accompanied by a sharp increase in temperatures in some areas. Jaisalmer in Rajasthan recorded a maximum temperature of 40.3 degrees Celsius, the highest reported in the country. Several parts of Jammu and Kashmir, Ladakh and north interior Karnataka also recorded temperatures more than five degrees above normal.
While the northwest turns progressively drier, the weather situation remains active over the eastern and southern parts of the country. A low-pressure area over the central Bay of Bengal has strengthened as it moves west-northwestwards.
The system was located over the east-central and adjoining west-central Bay of Bengal at 5:30 am on September 21. The associated cyclonic circulation extends to about 7.6 kilometres above sea level. Weather authorities indicate that the system could intensify into a depression over the west-central Bay within the next 24 hours and potentially deepen further during the following 24 hours.
The system is expected to move towards the west-northwest and may reach near the coast of northern Andhra Pradesh and southern Odisha by the morning of September 23. Its movement is likely to increase rainfall and wind activity along coastal areas.
Several states are expected to experience heavy rainfall on September 21. Weather authorities have warned of heavy showers over parts of the Andaman and Nicobar Islands, Chhattisgarh, coastal Andhra Pradesh, Karnataka, Madhya Maharashtra, Tamil Nadu, Puducherry and Karaikal, and Telangana.
Rainfall in some areas could reach between 64.5 to 115.5 millimetres. Thunderstorms accompanied by strong winds are also possible over Odisha, Jharkhand, Rayalaseema, coastal and south interior Karnataka, Tamil Nadu and Telangana.
Wind speeds may reach 40 to 50 kilometres per hour in some locations. Lightning and squally weather are also possible over coastal Andhra Pradesh, Gangetic West Bengal and north interior Karnataka. Parts of Assam and Meghalaya, eastern Rajasthan, Gujarat, Kerala, Konkan and Goa, Madhya Pradesh and Maharashtra may also receive thunderstorms and rain.
Delhi and the National Capital Region are expected to remain largely dry over the coming days. The capital may see partly cloudy skies at times, but the likelihood of significant rainfall remains low.
Delhi is likely to record a maximum temperature of around 36 degrees Celsius and a minimum of about 26 degrees Celsius. Northeasterly winds of 10 to 15 kilometres per hour may prevail during the morning.
With the monsoon retreating, residents could once again experience increased daytime heat, particularly during the afternoon.
The weather system is also prompting warnings for marine areas. Strong winds of 45 to 55 kilometres per hour, occasionally reaching 65 kilometres per hour, are expected over parts of the Bay of Bengal. Similar conditions are possible over portions of the Arabian Sea, including waters near the Somali coast.
Fishermen have been advised to avoid vulnerable marine zones and follow official weather warnings. Rough conditions are also expected around the Andaman Sea, the southern Myanmar coast and the Gulf of Mannar.
Farmers in rain-affected regions should maintain proper drainage, protect harvested crops and agricultural equipment, and avoid fieldwork during thunderstorms or lightning. Spraying fertilisers and pesticides during rainfall should also be avoided.
For the public, adequate hydration will remain important in areas experiencing renewed heat. During thunderstorms, people should stay indoors or move to safe shelters and avoid open fields, isolated trees and exposed locations.
India's weather is therefore entering a transitional phase: while the monsoon retreats from the northwest, a developing system over the Bay of Bengal is keeping large parts of the east and south on alert for heavy rain and strong winds.
