Droughts are most common in semi-arid and arid regions near the tropics and subtropics, with the Horn of Africa, the Sahel, Australia, the Middle East, and parts of western North America experiencing the highest frequency of severe drought events. Some of these areas, particularly in East Africa, cycle through major droughts every three to four years.
The Horn of Africa and the Sahel
Sub-Saharan Africa is the global epicenter of recurring drought. The Horn of Africa, which includes Kenya, Somalia, Ethiopia, Sudan, and Tanzania, has seen drought severity rise steadily over the past five decades. Major droughts struck the region in 1973–1974, 1984–1985, and 2010–2011, and the pattern has only accelerated. In recent years, multiple consecutive rainy seasons have failed entirely, pushing the Horn into prolonged, multi-year drought conditions that overlap before communities can recover.
The cycle now repeats roughly every three to four years, making the Horn one of the most drought-prone places on Earth. The vast majority of farming in the region depends entirely on rainfall, so even a single failed season can trigger food crises across millions of households. Historical rainfall data going back to 1920 shows that the longest unbroken drought periods in East Africa lasted three to four years, with particularly severe stretches from 1926 to 1929 and 1958 to 1961.
The Sahel, the belt of land stretching across West Africa just south of the Sahara, follows a similar pattern. This region experienced devastating droughts in the 1970s and 1980s that reshaped its population and agriculture. Drought frequency, intensity, and geographic spread have all been climbing across the Sahel, the Horn, and Southern Africa in recent decades.
Australia’s Interior and Southeast
Australia has one of the most drought-prone climates of any developed nation. Much of the continent’s interior is arid or semi-arid, and its rainfall is among the most variable in the world. The country’s drought history includes the Federation Drought (1895–1903), the World War II Drought (1937–1945), and the Millennium Drought (1997–2009), which lasted over a decade in parts of the southeast.
As of early 2026, severe rainfall deficiencies are concentrated across southeastern South Australia, most of Victoria, parts of southern New South Wales, and small pockets in southwestern Western Australia and coastal Tasmania. Some areas of South Australia’s Eyre and Yorke peninsulas, the Mid North, and the Murraylands have recorded their lowest rainfall totals for any comparable period since 1900. These agricultural heartlands are particularly vulnerable because they supply a significant share of Australia’s grain and livestock production.
The Middle East and Arabian Peninsula
The Middle East is already one of the driest inhabited regions on the planet, and drought conditions are intensifying. Climate projections for the Arabian Peninsula show drought frequency increasing across the board, with the sharpest rises in the northern parts of the region. Under higher-emission scenarios, some locations could see drought frequency climb by 300 to 400 percent by the end of the century compared to recent baselines.
Tehran offers a stark example of what this looks like in practice. Now in its sixth consecutive year of drought, Iran’s capital is approaching what water planners call “day zero,” the point at which municipal supply runs out entirely. Iran’s president has publicly raised the possibility of evacuating the city if conditions don’t improve. Cape Town, South Africa, and Chennai, India, have both come dangerously close to their own day-zero events in recent years, illustrating that the risk isn’t confined to one region.
Western North America
The western United States and northern Mexico form another major drought corridor. California, the American Southwest, and the Great Basin states experience frequent, prolonged dry periods driven by a combination of low annual precipitation, high summer temperatures, and heavy dependence on snowpack for water supply. The megadrought that gripped the southwestern U.S. from 2000 through the early 2020s was the driest stretch the region had seen in at least 1,200 years, based on tree-ring reconstructions.
Central America and the Caribbean also face rising drought risk. A zone known as the “Dry Corridor” runs through Guatemala, Honduras, El Salvador, and Nicaragua, where subsistence farmers regularly lose crops to failed rains. These areas sit in a climatic transition zone where even small shifts in seasonal rainfall patterns can push conditions from marginal to catastrophic.
Why These Regions Keep Drying Out
Geography is the primary driver. Most drought-prone areas sit in subtropical high-pressure belts where sinking air suppresses cloud formation, or in continental interiors far from moisture sources. Proximity to warm ocean currents, rain shadow effects from mountain ranges, and seasonal wind patterns all compound the problem.
Large-scale ocean cycles play a major role in determining when and where droughts strike. The El Niño-Southern Oscillation, or ENSO, is the most influential. During La Niña phases, the eastern Pacific cools, pulling moisture away from places like Ecuador, Peru, and the southeastern United States. El Niño shifts the pattern, bringing drought to Australia, Southeast Asia, and parts of southern Africa. These cycles don’t cause drought on their own, but they amplify existing vulnerabilities in regions that are already dry.
Rising global temperatures are layering additional stress on top of these natural patterns. Higher temperatures increase evaporation from soil and reservoirs, meaning that even if rainfall stays the same, the land effectively receives less usable water. The IPCC’s latest assessment found that every additional 0.5°C of global warming produces measurable increases in the intensity and frequency of agricultural and ecological droughts across multiple regions. Areas flagged for the steepest increases include western and central North America, the Mediterranean, southwestern and eastern southern Africa, Madagascar, and southern and eastern Australia.
The Mediterranean and Southern Europe
The Mediterranean basin is projected to be one of the fastest-drying regions in the world over the coming decades. Southern Spain, Italy, Greece, Turkey, and North Africa already experience hot, rainless summers, and winter rainfall, the season these areas depend on to recharge reservoirs and groundwater, has been declining. The IPCC projects increases in both the frequency and severity of agricultural drought across the Mediterranean with medium to high confidence. Parts of southern Europe are warming at roughly 1.5 to 2 times the global average rate during their hottest periods, accelerating soil moisture loss.
South America’s Vulnerable Zones
Brazil’s northeast, one of the most densely populated semi-arid regions in the world, has a long history of devastating droughts. The South American Monsoon region is also projected to see some of the highest increases in extreme heat, at 1.5 to 2 times the global warming rate, which compounds drought severity even during years with near-normal rainfall. Southwestern South America, including central Chile and western Argentina, has experienced a prolonged dry spell since roughly 2010 that mirrors the megadrought dynamics seen in the American West.
Half of the world’s 100 largest cities now sit in high water stress areas, a measure of how much available freshwater is being consumed relative to supply. The cities most at risk tend to cluster in exactly the regions outlined above: the Middle East, South Asia, sub-Saharan Africa, and the drier parts of the Americas. As these metropolitan areas continue to grow, the gap between water demand and drought-reduced supply is narrowing in ways that affect not just agriculture but the daily lives of hundreds of millions of urban residents.