Early Onset Doesn't Guarantee Good Rains: Experts Decode Monsoon 2026
Experts attribute changing monsoon patterns to interactions between monsoon weather systems, reports Ankita Kumari.
Published : June 3, 2026 at 6:40 PM IST
New Delhi: This year, the southwest monsoon made an early advance over the Andaman and Nicobar Islands. However, an early onset does not necessarily translate into above-normal seasonal rainfall. Scientists say that changing monsoon patterns are increasingly being influenced by interactions between monsoon weather systems and western disturbances, which originate in the Mediterranean region and affect weather conditions across India.
A good monsoon has traditionally been associated with prosperity and economic well-being, while a weak monsoon often brings distress. However, the character of the monsoon is changing. Instead of steady rainfall spread over several weeks, long dry spells are becoming more common, punctuated by short periods of intense rainfall. As a result, drought-like conditions and flooding can occur in the same season. These changes are posing challenges for agriculture, water-resource management and disaster preparedness.
The India Meteorological Department (IMD) has recently revised the normal dates for the onset and withdrawal of the southwest monsoon across different parts of the country.
Weather experts say climate change is an important factor behind shifts in monsoon circulation and rainfall patterns, although natural climate variability and ocean-atmosphere interactions also play a role
Why it matters
Even small shifts in the timing and distribution of monsoon rainfall can affect millions of farmers. In a changing climate, accurate monsoon forecasts are crucial for crop planning, water management, urban infrastructure, and preparedness for extreme weather events. Better seasonal forecasts can support preparedness for floods, droughts, heatwaves, and water shortages. It also helps people understand changing weather patterns more accurately.
According to Environmentalist Rajesh Paul, climate change is believed to be one contributing factor, although natural variability also plays a role. Rising temperatures in the atmosphere and oceans can influence monsoon circulation, moisture transport, and rainfall patterns. Scientists are increasingly observing changes in monsoon behaviour that are consistent with a warming climate, including more frequent extreme rainfall events and changing seasonal characteristics.
The analysis revealed shifts in both onset and withdrawal patterns across different regions of India. In some areas, the monsoon tends to arrive earlier than the historical average, while in others it arrives later. Similarly, withdrawal dates have also shifted. Researchers have also observed changes in rainfall distribution, with rainfall increasingly occurring through short-duration, high-intensity events rather than being spread evenly across the season.
Current updates
The southwest monsoon normally reaches Kerala around June 1 and advances across the rest of the country over the following weeks, usually covering the entire nation by mid-July. It typically begins withdrawing from northwest India in September.
This year, the monsoon reached the Andaman and Nicobar Islands on May 16, earlier than its normal schedule. However, despite the early advance over the Andaman Sea, its progress towards mainland India slowed, highlighting that an early onset in one region does not necessarily mean an early onset across the country. The monsoon normally reaches the northeastern states around June 5.
The southwest monsoon is likely to set in over Kerala during the next 24 hours. Isolated heavy to very heavy rainfall (7-20cm) is very likely over Kerala and isolated heavy rainfall over Tamil Nadu and Karnataka during the next 6-7days.
Moderate to Severe Thunderstorm activity with squally wind speeds up to 40 -50 kmph likely over many parts of Northwest, Central & East India and South Peninsular India during many days of the week.
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