Tamil Nadu Part Of Pronounced Drought Hotspot, 52-Year Study Finds

A 52-year climate analysis has identified Tamil Nadu as part of one of India’s more pronounced drought hotspots, with South Peninsular India recording the strongest long-term increase in drought-affected area among the country’s four broad climatic regions.

What the study examined

The study, titled ‘Evolution of Climate Extremes Over the Indian Subcontinent Using a Revised CEI’, was published in the International Journal of Climatology and analysed daily rainfall and temperature data from 1971 to 2022.

It assessed changes across multiple climate extremes using a revised India Climate Extremes Index, or IndCEI, developed by the researchers.

The revised index combines seven indicators, including heat, drought, dry spells, and heavy rainfall.

The study was conducted by scientists from the National Centre for Medium Range Weather Forecasting, India Meteorological Department, and Atria University.

The researchers used IMD’s 1° × 1° gridded rainfall and temperature datasets covering 1971, 2022 for the analysis.

South Peninsular India shows the strongest drought signal

The study found a strong positive trend in drought-affected areas over South Peninsular India, and said this trend was the strongest among the four regions examined.

South Peninsular India is the regional classification under which Tamil Nadu is placed in the study.

According to the analysis, less than 10% of South Peninsular India was affected by drought in much of the period before the 1990s.

In contrast, several years after 2000 saw more than 40% of the region under drought conditions.

The researchers noted that severe and persistent drought conditions were particularly evident during the 2010s and early 2020s.

A media note accompanying the research identifies Tamil Nadu, Odisha and Andhra Pradesh among the eastern coastal States where the area affected by drought increased by 20% to 30% during 2011, 2021, compared to the 1980s.

This places Tamil Nadu within a wider pattern of increasing drought exposure along parts of the eastern coast, as described in the media note accompanying the study.

Why SPEI matters in the drought assessment

The researchers used the Standardised Precipitation-Evapotranspiration Index, or SPEI, to assess drought.

Unlike an indicator based only on rainfall, SPEI incorporates both precipitation and potential evapotranspiration.

By including potential evapotranspiration, SPEI captures the influence of increasing temperatures on water availability.

This makes the drought assessment relevant not only to rainfall deficits, but also to the effect of heat on how much water remains available.

The study’s findings therefore connect the drought trend in South Peninsular India with a wider climate-extremes picture that includes both rainfall and temperature-related indicators.

Heat burden also rising in southern India

The findings also point to a growing heat burden over southern India.

The area experiencing high maximum-temperature extremes has increased in South Peninsular India, particularly since the 2010s.

The researchers said the increase in heat exposure could be linked to declining rainfall, urban heat-island effects, and broader climate change impacts.

The Heat Index, which combines temperature and humidity to indicate heat stress, also showed a steady increase over South Peninsular India.

The study attributes this intensification partly to rising minimum temperatures and high humidity associated with the region’s proximity to the Bay of Bengal.

Urbanisation and warmer sea-surface temperatures were also identified as factors that could amplify heat stress.

Together, these findings show that South Peninsular India’s climate-extreme profile is not limited to drought alone, but also includes increasing heat exposure and heat stress indicators.

Dry-spell indicator showed a flatter trend

The study found that consecutive dry days did not show a significant long-term increase over South Peninsular India.

The researchers recorded strong year-to-year variability in consecutive dry days, including a prominent peak in 2002.

Despite that variability, the overall trend in consecutive dry days was nearly flat.

The researchers cautioned that the use of May, October for this indicator may have dampened the long-term trend.

They said this possible dampening could be because the indicator included pre- and post-monsoon months.

Call for region-specific adaptation

The researchers said the findings underline the need for region-specific adaptation, particularly drought resilience in southern India.

The accompanying media note calls for a cross-sectoral response covering agriculture, water management, health, and infrastructure.

It also calls for finer-scale monitoring to identify localised climate extremes.

The study was published with the timestamp “Published - September 26, 2026 08:32 pm IST”.

Source: The Hindu