Drought: meaning, causes, types and facts

By the end of September 2025, about 85 per cent of Canada was abnormally dry or in drought. Most Canadians barely noticed. The shelves stayed full and the taps kept running.

In Somalia in 2022, drought-linked hunger killed an estimated 43,000 people. The hazard was similar. The outcome was not.

Why? The answer explains almost everything about drought. It is not only about the lack of rain. It is about what a family can fall back on when the rain stops.

This guide explains what drought means, what causes it and the main types. It also shares key facts, shows what drought does to children and looks at what really helps.

What is a drought? The meaning in one sentence

A drought is a long period with far less water than normal. It starts when rain or snow falls short for weeks, months or even years.

That shortage dries out soil, rivers and wells. It can hurt crops, animals and people.

A drought is not just a hot week or a short dry spell. It builds slowly and it lasts. In fact, the World Meteorological Organization says no other natural hazard is as easy to track, because its slow start gives time to watch it build.

That slow start matters. It gives us time to act, which means many drought deaths can be prevented.

Less than one per cent of the world's water is fresh water that people can easily reach, says the UN Environment Programme. When rain fails, that small supply shrinks fast.

The five types of droughts and why they happen in order

Scientists name five types of droughts. Most lists show them as a flat menu. In real life, they arrive as a chain.

1. Meteorological drought: rain or snow falls short.
2. Agricultural drought: soil dries out and crops struggle.
3. Hydrological drought: rivers, lakes and groundwater drop.
4. Socioeconomic drought: demand for water is greater than supply.
5. Ecological drought: ecosystems lose the water they need.

Think of a row of dominoes. First the rain fails. Then the soil dries. Then wells and rivers fall. Last, farms, jobs, food supplies and family budgets crack.

This order matters for two reasons. It shows why drought is a slow disaster. It also shows why drought deaths can be prevented, because there are months of warning before the last domino falls.

From a Canadian perspective, two newer terms are worth knowing.

A flash drought builds fast when heat, wind and low rain combine. In 2021, a summer heat wave dried out Prairie crops in just a few weeks.

A snow drought means the winter snowpack is too small. Much of Canada depends on melting snow to refill rivers, reservoirs and farm soil each spring. When the snowpack is low, water runs short all summer.

What causes a drought?

Drought has natural causes and human causes. Often the two feed each other.

Natural causes

Nature can switch off the rain in several ways:

• Weak rainfall: the weather systems that bring rain shift, stall or fail to form.
• El Niño and La Niña: swings in Pacific Ocean temperatures change rain patterns across the world.
• The jet stream: this fast river of air high above Earth can steer storms away from a region.
• Heat: hotter air pulls more water out of soil and plants, so the air gets thirstier.

Human causes

We do not control the rain. But people can make a water shortage worse:

• Deforestation and land damage: bare, worn-out soil cannot hold water, so rain runs off instead of soaking in.
• Groundwater over-pumping : wells are emptied faster than nature can refill them.
• Wasteful irrigation: old methods lose much of the water before it reaches the crop.
• Upstream diversion and dam management: water taken or held upstream leaves less for the people downstream.
• Climate change: a warming planet increases evaporation and shifts rain patterns, which makes droughts more frequent and severe.

Drought, famine, water scarcity and desertification: what's the difference?

These four terms are often mixed up. They are not the same thing.

• Drought: a shortage of rain or water over time.
• Famine: the most extreme level of food crisis.
• Water scarcity: too little usable water to meet people's needs. It can happen with or without drought.
• Desertification: fertile land turning into desert-like ground, mostly over the long term.

Think of drought as the hazard upstream. Hunger, malnutrition and famine are what can follow downstream. To go deeper on that end of the chain, read our guide to what is famine.

What are the effects of drought?

Drought reaches far beyond dry fields. Here's how it affects each part of daily life:

• Environment: soil cracks, rivers shrink and wildfire risk rises.
• Farming: crops fail and animals die. In Zimbabwe in 2024, the maize crop fell about 70 per cent and 9,000 cattle died.
• Energy: in Zambia in 2024, the Kariba Dam produced just seven per cent of its capacity. Power cuts lasted up to 21 hours a day.
• Trade: daily ship crossings at the Panama Canal fell from a normal 38 to 24 by November 2023.
• Health: unsafe water, disease and hunger all increase.
• Displacement: families leave home to search for water and food.

In Wajir, Kenya, families share a muddy water pan with their livestock. “It is heartbreaking to see my children drink this water,” says Habiba, a mother of 10. “They are thirsty, and there is no other option available to us.”

The costs keep climbing. The OECD says an average drought could cost 35 to 110 per cent more by 2035 than it does today.

What drought does to children

Drought sets off a chain. Crops fail, then families go hungry. Then children leave school, and some are pushed into work or marriage.

Here is what that looks like in the data:

• In Somalia, about 1.7 million children were expected to be acutely malnourished in 2025. About 1.84 million are expected to suffer acute malnutrition in 2026, including 483,000 severe cases.
• Child marriage more than doubled in Eastern Africa during the 2023 to 2025 drought, according to a UN-backed drought report. In Ethiopia, the rate doubled across the four hardest-hit regions. Some girls were married for dowries so their families could survive.
• Across Zimbabwe, many children dropped out of school because of hunger, costs and sanitation problems for girls.
• In Somalia's Gedo region, more than 1,100 children left school.

Drought destroyed the watermelon farm that fed Marwa ’s family in Somalia. At 15, she left home to work as a house help so her family could eat. “If this drought continues, two of them might die of starvation,” she says of her younger siblings. “And the rest of us—we might never go back to school.”

Paula Guastello, lead author of a UN-backed report on drought from 2023 to 2025, says coping methods grew “increasingly desperate.” She adds, “Girls pulled from school and forced into marriage, hospitals going dark and families digging holes in dry riverbeds just to find contaminated water—these are signs of severe crisis.”

For parents and teachers, this is the key point. Drought is not only a farming problem. It is a child protection emergency.

Why drought kills in some places and not others

Back to my opening question. Why did drought bring famine to Somalia but not to Canada?

Canadian families have savings, insurance, roads, stores and health care. Farmers have crop insurance. Payments rose from $893 million in 2018 to $4.9 billion in 2022 . In 2025, they were still $2.5 billion.

Many families in Somalia have far fewer safety nets. When crops and livestock are lost, there is often nothing else to fall back on.

When food ran out, Awo, a widow and mother of two in Gargaara, Somalia, had nothing left to give her children. “I put a pot on the fire with only water,” she says. “When they saw the steam, they believed food was cooking. They fell asleep waiting.”

Canadian farmers had insurance to fall back on. Awo had a pot of water. This is the clearest reason resilience spending works. The same drought hurts less when people are prepared.

What does drought look like in Canada?

Canada is not drought-proof. It is just better protected. Recent years show the strain:

• By the end of July 2025, 71 per cent of Canada's farmland was abnormally dry or in drought.
• In 2025, several places in the Maritimes had their driest summer on record.
• Saskatchewan's crop production fell 47 per cent in 2021.
• In Alberta, drought insurance for pasture paid a record $326.5 million for 2023.
• Hydro-Québec's exports were cut by more than half from 2022 to 2024. In 2024, its export revenue fell by $866 million.

British Columbia even has its own drought scale. The province's drought information portal uses six levels, from zero to five. Higher levels mean drier conditions.

The outlook is tougher. On the southern Prairies, droughts that once happened about once a decade may happen two or three times as often by late this century. That is true even under the lowest emissions scenario.

Can drought be prevented? What actually works?

No one can make it rain on demand. But we can stop a dry season from becoming a disaster. Here is what works:

• Early warning: trigger help before the last domino falls.
• Water harvesting: catch and store rain and runoff.
• Drought-tolerant seed: crops that need less water.
• Savings groups: families build a cushion for hard times.
• Regreening land: trees and healthy soil hold water.

Regreening has some of the strongest proof. Farmer Managed Natural Regeneration (FMNR) helps farmers grow trees from living stumps and roots already in the soil. It is cheap and simple.

A study by consulting firm Limestone Analytics found that FMNR returns US $2.06 for every US $1 invested. It looked at 40 projects in 19 countries between 2019 and 2023. Read more in our FMNR cost-benefit story.

The same study looked at projects that reached 13,315 households. It projects that 224 children under five will be saved over 20 years.

In Niger, FMNR has regreened about five million hectares. Tony Rinaudo of World Vision Australia, known as the Forest Maker, championed this method. World Vision and its partners aim to restore one billion hectares of land.

What World Vision is doing about drought

In Ethiopia, the RESILIENT-WE program ran for five years in East and West Hararghe. It was funded by Global Affairs Canada. It paired FMNR with fathers' groups, gender equality training and fuel-efficient cookstoves.

In 2025, 15,830 farmers applied sustainable farming methods, including FMNR. Another 133,267 people were trained in farming and livestock skills.

Across the organization, World Vision Canada reached 10.3 million people through 286 programs in 55 countries in 2025.

How you can help

You can help families get through drought before hunger sets in. Prepared communities cope better, and your support helps them get ready.

1. Give where the need is greatest.
2. Sponsor a child suffering from these problems.

Or share this article with a parent, a student or a teacher. Educators can use fast facts and the domino chain in class.

Frequently asked questions

Is 2026 going to be a drought year?

In some places, yes. East Africa faces severe drought right now. For Canada, check the latest Canadian Drought Monitor maps for your region.

How long can a drought last?

A drought can last a few weeks or several years. Flash droughts build in weeks. Others drag on through many rainy seasons, as in parts of East Africa now.

What are the three main types of drought?

The three main types are meteorological, agricultural and hydrological. Socioeconomic and ecological drought complete the five.

How is drought measured?

Experts use tools such as the Standardized Precipitation Index and the Palmer Drought Severity Index. Canada and the United States publish drought monitor maps. British Columbia uses its own six-level scale.