India’s monsoon hits halfway mark: Why July witnessed prolonged wet and dry spells

Low-pressure systems form when warm air heats up, expands, and rises into the atmosphere. These can cause unstable and cloudy weather, stormy conditions, and strong winds. During monsoon, these are the main rain-bearing systems.

The spatial and temporal rainfall distribution remained skewed throughout the month. Floods ravaged Gujarat, Saurashtra (in Gujarat), Assam, Odisha, and Jammu while dry spells prolonged over Bihar (seasonal rainfall was -42%), Andhra Pradesh (-35%), Kerala (-34%), Karnataka (-24%), Haryana and Uttar Pradesh (-27%) this season.

Rainfall in the last few days eliminated much of the deficit and the India Meteorological Department (IMD) said that during July 1-29, the country received normal rainfall. The same for July 1-30 was 13.9% below normal compared with the long period average (LPA). LPA is the mean rainfall recorded over a region for a specific time frame, calculated across a multi-decade span of 30 to 50 years.

The all-India rainfall came close to normal for the first time in this season so far as July came to a draw. The country has, since June 1, recorded 389.8 mm (-12.6% from normal of the LPA). Notably, the day-on-day all-India rainfall remained below the normal mark (see red bars in the graph).

The progress of the monsoon season in 2026. Source: IMD

Table 1: Week-wise rainfall (% departures) over India. Source: IMD

Behind prolonged dry and wet periods

The monsoon onset over the regions in the north, northwest, and western India was realised on July 9. The first good spell was a result of the season’s first low pressure system that developed in the Bay of Bengal off the Odisha coast. This system lingered on and its slow movement, supplemented by strong monsoonal winds from the Arabian Sea, brought widespread, heavy rainfall across the west coast, central, and northwest India regions during July 1-9.

During July, all the rainfall events were linked to multiple active weather systems and their simultaneous interplay. July saw the development of four low pressure systems, two of which intensified into deep depressions. As a result, the central India region between Odisha and Gujarat experienced wet conditions for most days. The slow movement of the two low pressure systems also had a role to play in the continuous rainfall. The IMD said that there were 24 days when the country was affected by low pressure systems, which was double the average for July (normal is 13.5 days). July 2026 thus saw the highest low pressure-affected days over India since 2017, the IMD data said.

The monsoon trough’s position — an elongated low-pressure area extending from Pakistan to the Bay of Bengal that brings heavy seasonal rainfall — was in favour during early July, which further enhanced rainfall and kept monsoon conditions active during early and late July.

The dark blue regions have recorded above-normal rainfall whereas regions in red are rainfall-deficit regions. Source: IMD

During most July days, below-normal rainfall was experienced over the south peninsular and northwest regions. During this period, there was a sharp spike in the temperatures, with places in Andhra Pradesh and Vidarbha in Maharashtra reporting heatwave conditions.

In summary, July experienced extreme wet conditions resulting in flooding and landslides in Gujarat, Assam, Maharashtra, and Odisha to hot and dry conditions resulting in heatwaves — a rare phenomenon for the month. July this year ended as south peninsular India’s warmest (with respect to minimum temperatures) and second warmest (with respect to maximum temperatures) — a direct link to below-average rainfall.

Record rainfall

Umargam in Gujarat’s Valsad district recorded 1067 mm in 24 hours. It became the third wettest single-day rainfall event ever recorded in the country after Sohra in Meghalaya (1563.3 mm on June 16, 1995) and Aminidivi in Lakshadweep (1168.5 mm on May 6, 2004). IMD called the Umargam’s rainfall “exceptionally” heavy, a term referred to when the 24-hour rainfall over a location crosses 210 mm or touches the near-records mark.

“These are meso-scale (affecting an areas within 10km radius) and can be triggered by a combination of factors: weather systems, local land and water bodies, cloud interactions,” noted Mrutyunjay Mohapatra, director general, IMD. “Every year, there are extreme rainfall events but these get 10 per cent enhanced in the presence of a low pressure system, studies have shown.”

Gujarat, Odisha, and Maharashtra reported the highest “exceptionally” heavy rain events in July, followed by Maharashtra, Chhattisgarh, Uttarakhand, Uttar Pradesh, Jharkhand, Assam, and Meghalaya. For at least 24 days of the month, there was at least one location — if not more — that recorded such “exceptionally” high rainfall.

Table 2: Exceptionally heavy rainfall (more than 220mm) across states in July. Source: IMD

For comparison, Chandigarh’s annual rainfall is 1070 mm while Umargam recorded 1067 mm in 24 hours. Amritsar’s annual rainfall is 724 mm while Ahmedabad recorded 720mm in 24 hours on July 27. Mahabaleshwar received 1/10th of its annual rainfall on July 6 (see Table 2). Kaprada in Gujarat received 420 mm in a day, which was close to Jodhpur’s annual rainfall (411 mm).