India Records 8% Above-Normal Monsoon Rainfall in 2025: IMD

India’s 2025 southwest monsoon delivered eight per cent more rainfall than normal, according to the India Meteorological Department (IMD). The season, lasting from June to September, boosted water storage and aided crops, but it also caused deadly floods in parts of northern India. Behind the uneven spread lay a complex interplay of atmospheric and oceanic systems, including the Somali Jet and the Tibetan Plateau’s heating effect.

The Story

This year’s monsoon brought a national average of 93.7 cm of rainfall, placing it among the wettest in recent decades. The surplus was most pronounced in northwest India, which received nearly 27% more than its seasonal average, the highest since 2001. Central India and the southern peninsula also enjoyed good rainfall, with surpluses of 15% and 10% respectively. In contrast, the east and northeast regions saw one of their driest years on record, receiving only 80% of their normal quota, the second lowest since 1901.

The monthly distribution showed a steady rhythm, with above-normal rainfall in all four months. September was particularly wet, with 15% excess rainfall. The season also featured seven monsoon depressions in the Bay of Bengal and Arabian Sea, one of which intensified into a deep depression. These storms lingered longer than usual, extending heavy spells over many parts of the country.

The monsoon’s onset was also ahead of schedule. It reached the Andaman and Nicobar Islands on 13 May, almost nine days early, arrived in Kerala on 24 May instead of 1 June, and covered the entire country by 29 June. Though its withdrawal has been slower than usual, the IMD does not count October rains within the seasonal tally.

Concept: The India Meteorological Department (IMD)

Established in 1875, the IMD is India’s national weather agency under the Ministry of Earth Sciences. Its roles include:

• Monitoring monsoons and issuing forecasts.

• Warning systems for cyclones, floods, and extreme weather.

• Advisories for agriculture, aviation, and shipping.

• Climate data and research for long-term planning.

The IMD is also a Regional Specialized Meteorological Centre (RSMC) for cyclones under the World Meteorological Organization (WMO), coordinating forecasts across South Asia.

Concept: The Indian Monsoon

The monsoon is a seasonal reversal of winds, caused by differential heating of land and sea.

• Southwest Monsoon (June–September): Moist winds from the Indian Ocean bring 70% of annual rainfall.

• Northeast Monsoon (Oct–Dec): Retreating winds bring rain to Tamil Nadu and coastal Andhra Pradesh.

It is not uniform: some regions face surplus, others deficit — making it both a blessing and a risk.

Why It Matters

The monsoon is the “lifeline of India’s economy”:

1. Agriculture: Nearly 55% of India’s net sown area depends on monsoon rains.

2. Water Security: Reservoirs, aquifers, and rivers are replenished by monsoon rainfall.

3. Economic Stability: Food prices, inflation, and rural incomes are directly shaped by monsoon performance.

Without a reliable monsoon, India’s water and food systems face strain.

Background / Context

Drivers of Monsoon Dynamics

1. Somali Jet:
   A strong low-level jet stream over the Arabian Sea, blowing from Somalia towards the west coast of India. It transports enormous amounts of moisture, fueling the southwest monsoon. A stronger Somali Jet usually means heavier rains in peninsular and central India. In 2025, a robust Somali Jet enhanced rainfall over western and southern regions.

2. Tibetan Plateau Heating:
   Known as the “Third Pole,” the Tibetan Plateau acts as a massive heat source in summer. Its elevated heating creates a thermal low, strengthening the monsoon circulation. Without Tibetan heating, the monsoon trough weakens. This year, strong pre-monsoon heating over Tibet supported an early onset and robust flow into North India.

3. El Niño–Southern Oscillation (ENSO):
   While El Niño often weakens the monsoon and La Niña strengthens it, the link is not absolute. IMD has indicated a developing La Niña in the Pacific, which could influence winter conditions.

4. Indian Ocean Dipole (IOD):
   A positive IOD (warmer western Indian Ocean) boosts rainfall, while a negative IOD dampens it. Seasonal variability of the IOD has influenced India’s uneven rainfall.

5. Western Disturbances:
   Mediterranean-origin storms interacted with the monsoon trough, intensifying extreme rainfall in northern states.

6. Cyclonic Activity:
   Depressions in the Bay of Bengal and Arabian Sea significantly contributed to prolonged spells.

Historical Context

• Long Period Average (LPA): ~88 cm for June–September.

• Major droughts: 1918, 1972, 2009, 2015.

• Record surpluses often coincide with strong Somali Jet phases or positive IOD events.

Timeline of the 2025 Monsoon

• 13 May: Monsoon entered Andaman & Nicobar Islands (nine days early).

• 24 May: Onset in Kerala (seven days early).

• 29 June: Entire country covered by monsoon.

• Sept 2025: Surplus rains peaked at +15% above average.

• 30 Sept: IMD declared 8% overall surplus, fifth-highest since 2001.

Implications

For Agriculture:

• Boost for kharif crops (rice, pulses, oilseeds) due to improved soil moisture.

• Better reservoir storage supports rabi crops (wheat, mustard).

• Localized crop losses in Punjab, Haryana, and UP due to flooding.

For Economy:

• Higher agricultural output reduces inflationary pressures.

• Rural demand likely to rise, boosting consumption-driven growth.

• Flood-related infrastructure damage may offset some gains.

For Society:

• Surplus rainfall improved water availability in drought-prone regions.

• Northeast faced drought-like stress, affecting tea, jute, and rice farmers.

• Flood-hit communities in North India experienced displacement and livelihood loss.

For Climate Discourse:

• Extreme rainfall events reflect growing climate volatility.

• Regional imbalances highlight the importance of localized climate adaptation.

• Strengthening disaster management and early warning systems is critical.

Conclusion

India’s 2025 monsoon season illustrates the paradox of abundance and scarcity: an 8% surplus nationally, yet severe floods in the North and deficits in the Northeast. The dynamics of the Somali Jet, Tibetan Plateau heating, and ocean-atmosphere interactions underline how interconnected global systems shape India’s rainfall. For policymakers, the lesson is clear — managing water, agriculture, and disaster risks requires a climate-resilient approach that respects the monsoon’s complexity.