Assam and Meghalaya Face Sixth Consecutive Year of Below-Normal Monsoon Rainfall
Monsoon Deficits in Assam and Meghalaya
Guwahati, Oct 1: The monsoon season has once again fallen short in Assam and Meghalaya, marking the sixth consecutive year of below-average rainfall, raising alarms about the shifting rainfall patterns in this rain-dependent region of India.
The four-month southwest monsoon period concluded with the Assam-Meghalaya meteorological sub-division experiencing a 31% deficit, receiving only 1,204.6 mm of rain compared to the normal 1,784 mm, as reported by the India Meteorological Department (IMD).
Meghalaya, known for its heavy rainfall, faced an even steeper deficit of 39%, while Assam recorded a 26% shortfall.
The broader Northeast region also saw a lack of rain. With the exception of Nagaland, all other states in the Northeast reported below-normal rainfall, with Arunachal Pradesh experiencing the highest deficit at 45%.
Throughout the monsoon season, cumulative rainfall in the IMD’s East and Northeast India homogeneous region remained below the expected levels.
This latest deficit continues a concerning trend of insufficient monsoons in Assam and Meghalaya. Following a 29% excess in 2020, the region has since recorded deficits of 18%, 9%, 17%, 15%, and 36% in the subsequent five years.
The situation became particularly alarming in 2025, when Assam and Meghalaya received merely 1,123.4 mm of rainfall, the lowest seasonal total since 1901.
Historically, the region has rarely experienced a normal or surplus monsoon. Prior to 2020, above-normal rainfall was recorded only once in 2012, indicating that the monsoon has been below normal in 13 of the last 15 years.
Noted meteorologist Professor Bhupendra Nath Goswami, former Director of the Indian Institute of Tropical Meteorology, attributed the contrasting rainfall trends between India and the Northeast to climate change.
“While the average rainfall across India, especially in some western states, is on the rise, the Northeast is witnessing a decline due to climate change,” Goswami explained.
He further noted that increased atmospheric moisture linked to climate change is leading to more frequent and intense rainfall extremes, characterized by short bursts of heavy rain followed by drought periods.
“This trend is unlikely to change soon,” he added.
Uneven Rainfall Across Assam
The rainfall distribution within Assam was notably uneven. Two districts, Nalbari (with a 61% deficit) and Udalguri (60% deficit), were classified as ‘largely deficient’, while ten districts experienced ‘normal’ rainfall, and the rest were categorized as ‘deficient’. The shortfall was particularly severe in traditionally wet areas.
Sohra: A Legacy of Rainfall Diminishing
In Sohra, formerly known as Cherrapunji, the seasonal deficit reached 35%, reflecting the changing rainfall dynamics even in a location famed for its heavy monsoon rains. The East Khasi Hills town recorded a 40% deficit in June, followed by 15% in July, 30% in August, and a staggering 70% in September. These figures are significant for a region historically associated with some of the highest rainfall totals globally.
Guwahati: A Disparate Monsoon Experience
Guwahati experienced a highly uneven monsoon season. The city recorded approximately 70% excess rainfall in July, but the other months saw significantly below-normal levels. June had deficits of around 60%, while August and September also ended below normal. Overall, Guwahati received about 7% less rainfall than average during the season, with much of the deficit compensated by the unusually wet July.
However, the rainfall in Guwahati was concentrated in a few heavy events. Aside from two days of intense rain in July, the city only exceeded 50 mm of rainfall once during the entire season, in August. Additionally, Guwahati's mean maximum temperature remained about 1 degree Celsius above normal throughout the monsoon, highlighting another aspect of the region's changing weather patterns.