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India has seen intense rainfall in recent weeks, with some areas experiencing flood and flood-like situations. Yet as August began, over a third of the country’s land area was under different categories of drought, according to the India Drought Monitor maintained by IIT Gandhinagar.
Forecasts suggested the situation may not ease soon. Scientists tracking soil moisture say that drought is likely to persist across large parts of the country over the coming month, even in regions that have already seen rain.
This comes against a backdrop of an overall rainfall deficit: India had received 12 per cent less rainfall than normal as of August 11, according to the India Meteorological Department (IMD).
For farmers, the timing matters particularly as the kharif season is already under way and August falls in the middle of the kharif season, when crops such as rice, pulses, cotton, and oilseeds depend on sustained soil moisture through their critical growth stages. Persistent or recurring dry spells at this point can lower yields even if the season’s total rainfall looks normal on average.
The risk is particularly significant for farmers who have already had a delayed start to the season and now face uneven rainfall during the crop-growth period. Scientists tracking the situation say the drought may also carry into the rabi season that follows, through its effect on groundwater used for irrigation.
According to the India Drought Monitor, the most severely affected states, by share of area under drought, were Sikkim (80.8 per cent), Arunachal Pradesh (78.3 per cent), Andhra Pradesh (72.4 per cent), Mizoram (68 per cent), Goa (67.9 per cent), and Delhi (65.2 per cent). The least affected are Nagaland (1.3 per cent), Gujarat (2.7 per cent), Tripura (9.9 per cent), and Rajasthan (10.8 per cent).
Regionally, northeast India was the worst-hit, with about 58 per cent of its area under drought, followed by west India at 43 per cent and south India at 40 per cent. North, east and central India were each at about 34 per cent, while northwest India was comparatively unaffected at around 11 per cent.
A separate measure, IMD Pune’s Aridity Anomaly Index, pointed to a similar trend: roughly 20 per cent of India’s districts were classified as mildly arid, 12 per cent as moderately arid, and 6 per cent as severely arid.
Scientists say that the apparent contradiction between heavy rainfall and widespread drought was largely explained by how rapidly the rain is arriving, and how long the soil can retain the moisture.
Karthikeyan Lanka, associate professor at IIT Bombay, told Down To Earth that researchers are seeing an unusual “swing” in drought conditions. A location can remain under drought for a week or two, briefly move out of drought after a rainfall event, and then slip back into drought soon after.
There has been a pattern where rain does fall — sometimes heavily — but doesn’t translate into sustained root-zone moisture. “Momentarily soil will be wet, but then there will be long dry periods,” Lanka said. During these dry spells, infiltration is followed by evaporation and plant transpiration, causing soil moisture to fall again.
Lanka is the principal investigator of the institute’s ‘All India Experimental Agricultural Drought Forecasts’.
His team at IIT Bombay’s Ecohydrology Group (with researchers Saurabh Verma, Sarthak Somani, and Aditi Goel) tracks soil moisture, along with rainfall, temperature, vegetation, and vapour pressure deficit and evapotranspiration.
The key variable is soil-moisture anomaly — the difference between the moisture expected under normal climatological conditions (average of nine years from 2015-2024) and what is actually observed in a particular week. The system uses data from the SMAP (Soil Moisture Active Passive) satellite, which provides soil-moisture information across India at about 9-km resolution, and other data from IMD and ERA5 datasets.
Source: Centre for Climate Studies, IIT Bombay
The forecast maps for the four successive weeks — August 3-9, 10-16, 17-23 and 24-30 — show severe-to-exceptional drought categories persisting across the Indo-Gangetic belt and parts of the peninsula, even as the monsoon season continues.
This drying is not confined to the surface. Satellite observations typically provide soil-moisture information for the top 5 cm of the soil, which responds quickly to rainfall and can also dry out rapidly. Lanka and his team, however, are tracking moisture through the top 100 cm, the root zone. This layer normally changes more slowly, but researchers are now seeing similar swings even at this depth.
“The root zone is normally far more stable. But we are seeing swings happening even at the root-zone level,” Lanka said.
The extent of the swing also depends on soil type, and on factors like how well it absorbs water, how well it retains what it absorbs, and how much rainfall is lost as run-off rather than soaking in.
These swings are particularly visible in parts of Madhya Pradesh, Karnataka, southern Tamil Nadu and Rajasthan, he said. In other areas, including parts of Andhra Pradesh, Uttar Pradesh, Bihar, Jharkhand, Punjab and Haryana, soil moisture has not recovered for weeks at a stretch.
“There are other locations where we are observing persistent drying. Week after week, the situation is not improving. There were sporadic rainfall events, but not sufficient to push soil moisture above normal levels,” Lanka said.
The forecasts, disseminated through the Centre for Climate Studies at IIT Bombay, project drought categories one to four weeks ahead, based on deviation from a nine-year (2015–2024) climatological baseline.
For agriculture, the immediate concern is the ongoing kharif season. “There may be crop yield loss in kharif,” Lanka said.
There is also a less visible risk to groundwater. If farmers increase groundwater pumping to compensate for inadequate rainfall and meet kharif crop water requirements, groundwater reserves could come under additional stress, with consequences for the rabi season.
“Considering droughts to persist in these regions, adaptation and contingency planning for rabi may need to begin now, particularly around crop choice, sowing windows, irrigation, and water availability,” the IIT Bombay forecast noted.