About the India Drought Monitor
What is the IDM?
The India Drought Monitor (IDM) is a map updated every week, showing where drought is and how bad it is across India and its union territories. The map is built on a Combined Drought Index (CDI) and uses six classifications: normal conditions, Abnormally Dry (D0) — showing areas that may be going into or coming out of drought — and four levels of drought: Moderate (D1), Severe (D2), Extreme (D3) and Exceptional (D4).
The monitor is best explored through the interactive map, where you can hover for the exact index value at any location, zoom to any state, and animate conditions week by week back to 2021.
Who draws the map?
The India Drought Monitor is produced by the Water and Climate Lab (WCL) at the Indian Institute of Technology Gandhinagar, drawing on hydro-meteorological data from the India Meteorological Department (IMD) and the Central Water Commission (CWC), satellite products from ISRO / NRSC, and global reanalysis and remote-sensing datasets. The index is computed and reviewed each week, combining several indicators into a single drought picture for the country.
How do we know when we're in a drought?
When you think about drought, you probably think about water — or the lack of it. Rainfall plays a major role, but the Combined Drought Index considers many data sources at once. The numeric inputs include the Standardised Precipitation Index (SPI), the Standardised Runoff Index (SRI), the Standardised Soil Moisture Index (SSMI), along with temperature, evaporative demand and vegetation health. No single piece of evidence tells the full story; the CDI blends these standardised indicators so that meteorological, agricultural and hydrological drought are all reflected in one map.
How fast does the map change?
Recognizing emerging drought, or determining when a drought is over, entails understanding what's normal for a given location and season and observing both short- and long-term weather patterns. If an area has been in drought for a while, it usually takes more than one or two rains to end it. Intense heat can also make things dry out quickly, but as an established practice the map doesn't shift more than one category per week in either direction except in the most extraordinary cases.
Does the IDM look back or forward in time?
The India Drought Monitor includes both. The core map looks back in time, providing a "snapshot" of very recent conditions built on data through the previous week. Alongside it, the monitor also publishes short-range outlooks (7-, 15- and 30-day forecasts of the index), so users can see both where drought has been and where it may be heading.
Who uses it, and what do they do with it?
Drought information of this kind supports a wide range of decisions — from state agriculture and relief departments assessing crop stress, to water-resource managers tracking reservoir and groundwater conditions, to researchers studying the monsoon and climate variability. National bodies such as the National Disaster Management Authority and the Department of Agriculture's drought-management framework rely on multi-indicator assessments when evaluating drought severity. The IDM is a scientific monitoring product; it informs these assessments but does not, in itself, trigger any administrative or political action.
How does drought affect the country?
Drought is a normal part of the climate. It tends to be a slow-moving hazard, which can cause people to underestimate the damage it can do — but losses from drought may be as substantial as those from hurricanes, tornadoes and other disasters. Drought causes losses to agriculture; affects domestic water supply, energy production, public health and wildlife; and contributes to wildfire, to name a few of its effects.
About the Data
IDM data are provided as gridded text grids (latitude, longitude, value) for the Combined Drought Index and its component indices, along with state and national boundary files — head to Data Download for access. The weekly CDI time series extends from 2021 to the present and powers the interactive map's animation. We ask only that you cite the India Drought Monitor and the Water and Climate Lab, IIT Gandhinagar, when using the data in publications.
How can I get involved?
Want to learn more or contribute to the IDM effort? Here are some ways:
- Explore the interactive map — inspect the index anywhere in India and animate the historical record on the Interactive Map.
- Share local impact reports — on-the-ground observations of crop, water and pasture conditions help validate the index.
- Use the data in research — the gridded indices are designed for hydro-climatic analysis; we welcome collaboration.
- Get in touch with the lab — reach the Water and Climate Lab at IIT Gandhinagar with questions or feedback.