The India Meteorological Department (IMD) has forecast that the southwest monsoon is likely to reach Delhi and the wider National Capital Region (NCR) between 25 June and 30 June, giving residents a clearer window for the arrival of the season's rains. The forecast follows a spell of thunderstorms and scattered showers on Thursday, 6 June, which offered temporary relief from weeks of punishing summer heat.

Monsoon Timeline and Progression

The southwest monsoon made its onset over Kerala on 4 June, three days behind its normal date and five days after the IMD's initial projection. Despite the delayed start, weather experts expect the system to advance steadily, covering most parts of the country by the third week of June.

According to the IMD's monsoon progression map, Delhi, Noida, Gurugram, and Ghaziabad are all in the 25–30 June onset window. The weather system is also forecast to push into parts of Haryana, Punjab, and Chandigarh during the same period. Several northern and hilly regions — including parts of Himachal Pradesh, Jammu and Kashmir, and Ladakh — may also receive rainfall around the same time.

Western Disturbance Brings Interim Relief

A Western Disturbance that became active around 3 June has already delivered relief to millions across North India, where temperatures had remained exceptionally high for weeks. Meteorologists have, however, cautioned that sudden heavy-rain spells could cause waterlogging in urban areas, while strong winds and lightning pose risks in open spaces and mountainous terrain.

The IMD forecast continued thunderstorm and rainfall activity across several areas on 6 June, after which conditions are expected to gradually stabilise. Temperatures are likely to rise again once the current spell subsides, and may stay elevated until the monsoon advances further north toward the end of the month.

Historical Context

Last year, the southwest monsoon reached Delhi on 29 June — two days later than its normal onset date of 27 June, based on the 1961–2019 climatological average. The current forecast of a 25–30 June window places this year's arrival broadly in line with recent patterns, though the delayed Kerala onset has kept uncertainty elevated.

Air Quality Remains a Concern

Despite the rain-driven temperature dip, Delhi's air quality continued to languish in the 'poor' category on 6 June. Anand Vihar recorded the city's highest Air Quality Index (AQI) reading at 284, followed by Mundka at 239, Wazirpur at 214, Okhla Phase-2 at 208, and IIT Delhi at 187. Experts note that pre-monsoon showers provide only short-lived AQI relief; sustained improvement typically requires the full onset of the monsoon and consistent rainfall.

With the monsoon's arrival still weeks away, residents across Delhi-NCR can expect further heat spells interspersed with occasional thunderstorm activity before conditions change decisively.