Global Extreme Weather and Climate Change Dashboard

Drought

Drought accounts for about 7% of global weather/climate economic losses but the single largest share of deaths, about 33%, 1980-2025 (see Loss Normalization) -- famine-driving droughts in Africa dominate that toll. "Drought" names three different deficits, and this page measures each one separately rather than folding them into a single number. Meteorological drought is a rainfall deficit. Agricultural drought is a soil-moisture deficit -- the water a crop can actually reach, which lags rainfall because the soil store has to draw down first. Hydrological drought is a deficit in river flow and the groundwater and snowpack feeding it -- the water people actually withdraw. Every index below ranks each location against its calendar-month history and classifies the result into the same USDM-equivalent D0-D4 categories, so the three panels read the same way and can be compared directly.

Variables on this page

Every variable below is evaluated over a full reliable-trend window against the combined "detected change" standard (IPCC's likelihood criterion plus a magnitude-vs-variability check -- see the homepage or Methodology for the full definitions). Shown as alternative ways of characterizing this same phenomenon -- some from independent sources, others a different construction on the same underlying data (each variable's note says which).

The precipitation-only (SPI-style) series matches two independently well-documented global drought years: 2021 ranks as the single highest year in this 1979-2026 record (the Horn of Africa's worst drought in 40 years began that year, alongside a severe western North America megadrought and Madagascar's near-famine drought), with 2011 second (the Horn of Africa famine, the historic Texas/Southern Plains drought).

The three drought types agree on where, and disagree on how much. Taking each at its D2+ (severe or worse) default, Africa andSouth America show a detected increase on all three independent measures -- rainfall, soil moisture and river flow, built from two unrelated data sources. Europe, North America and Oceania show none on any of the three. Asia shows one only in soil moisture (+1.68 points/decade, p=0.022). Three different physical quantities converging on the same two continents is a stronger result than any one of them alone, and the three continents where nothing is detected are as much a part of that result as the two where it is.

Globally, though, the three diverge. Agricultural drought showsno detected global trend at any severity level in the root-zone series (D2+: +0.81 points/decade, p=0.40): the regional signals in Africa, Asia and South America do not aggregate into a global one, because the rest of the world's land area shows nothing. The surface (0-7cm) series runs steeper than the root zone at every level, which is what a faster-responding shallow layer should do, but only one of its ten severity levels clears both detection bars -- with ten levels on the table that is close to what chance alone would produce, so it is not read here as a finding. Africa's soil-moisture result is a genuine borderline case: it clears the flat 10% significance bar at p=0.079 but not the multiple-comparisons-adjusted bar, and themethodology page lists it among the results that flip.

Hydrological drought separates from rainfall. The river low-flow index shows a detected increase globally at every severity level (D2+: +0.76 percentage points per decade, p=0.013), while the precipitation-only series at the same severity clears statistical significance but stays inside this site's variability bar, so it registers no detected change. The pattern lines up with the AED-inclusive series rather than with rainfall: the drying shows up in the metrics that track evaporative demand and actual water availability, and not in precipitation alone. Regionally the low-flow index detects an increase in Africa (+2.06 points/decade) andSouth America (+3.01 points/decade) and detects nothing in Asia, Europe, North America or Oceania -- the same two continents the precipitation-based index singles out, reached through a different measurement.

The index recovers documented events without being told about them: its worst years are 2023, 2024, 2022 and 2025 (the Amazon and Panama Canal droughts, the Yangtze and European drought of 2022), then 2015 and 1983, the two strongest El Ninos of the later 20th century. The record starts in 1982 rather than 1979 because GloFAS's model groundwater store is still draining over the reanalysis's first years; leaving those years in would suppress early drought and manufacture a drying trend out of a model artifact. That cutoff is not what produces the trend -- recomputing from scratch at start years from 1979 to 1995 moves Sen's slope only between +0.55 and +0.87 points per decade.

The precipitation-minus-AED (SPEI-style) series replicates and extends through the present the central finding of Vicente-Serrano et al. 2022 ("Global drought trends and future projections," Phil. Trans. R. Soc. A 380: 20210285): including atmospheric evaporative demand reveals a much stronger drying trend than precipitation alone shows. Comparing 1980-2002 to 2003-2025, the precipitation-only series' global drought trend rises +0.93 percentage points, while the AED-inclusive series rises +3.35 pointsover the identical window -- more than 3x larger. 2023, the hottest year on record globally at the time and a documented case where extreme heat (not just low rainfall) drove severe drought, shows the AED-inclusive series notably worse (13.4%) than the precipitation-only series (10.8%) for that year. See the methodology page for the Hargreaves-method simplification this uses in place of the source paper's full Penman-Monteith calculation.