El Niño Brings Heat, Drought and Flood Threats to the South-West Indian Ocean Region

The South-West Indian Ocean Climate Outlook Forum has urged governments and communities to prepare for these differences instead of relying on a single regional forecast.

A strengthening El Niño is expected to reshape temperature, rainfall and tropical cyclone patterns across the South-West Indian Ocean from October 2026 to March 2027, bringing a mix of threats that could affect harvests, drinking water, public health and coastal livelihoods. Communities across the region face different risks, with southern areas more exposed to drought, northern areas facing heavier rainfall, and island States needing to prepare for several hazards at once.

The South-West Indian Ocean Climate Outlook Forum has urged governments and communities to prepare for these differences instead of relying on a single regional forecast. Its outlook covers October–December 2026 and January–March 2027, offering a seasonal picture that can help farmers, water managers, health services and emergency teams plan for conditions that may put pressure on everyday life.

Southern communities face mounting pressure on food and water

Drier conditions are expected across much of the southern region, particularly South Africa, southern and central Mozambique, Malawi and south-western Madagascar, where reduced rainfall could leave soils short of moisture, weaken pasture and strain water supplies. For households dependent on farming or livestock, the combination of drought and heat could reduce agricultural productivity and threaten food security, incomes and livelihoods.

Above-normal temperatures are forecast across the entire region, with a substantially increased likelihood of exceptionally high temperatures adding to concerns about water stress and health. Madagascar's rainfall outlook varies across the island: northern and eastern areas are more likely to receive normal to above-normal rainfall, and the south-west faces a greater threat of below-normal rainfall and drought stress, making locally tailored preparation especially important.

Heavier rain raises flood and contamination risks in the north

Parts of Tanzania, northern Malawi, Seychelles and the Mascarene Islands are expected to experience wetter conditions, increasing the risk of floods, flash floods and landslides that could damage infrastructure and disrupt communities. Excessive rainfall can also damage crops and contaminate water supplies, creating overlapping pressures on food production, clean water access and public health.

These contrasting rainfall signals mean preparation needs to reflect the conditions expected in each location, with drought and water-security planning in southern areas and stronger flood and landslide preparedness in northern and wetter areas. Island States need a flexible approach covering extreme heat, heavy rainfall, marine impacts and tropical cyclones, as changes across the ocean and atmosphere could also affect marine ecosystems, fisheries and the people who depend on them.

A quieter cyclone season still carries local danger

Tropical cyclone activity is expected to be below normal across the South-West Indian Ocean basin overall under the influence of El Niño, with cyclone tracks projected to shift southward. That shift could reduce landfall risk for Madagascar and Mozambique, although the Mascarene Islands retain a near-normal cyclone risk; fewer cyclones across the basin do not remove the possibility of a damaging storm in an individual community.

The outlook was developed at a forum hosted by the Seychelles Meteorological Agency from 15–17 September, bringing together participants from Comoros, La Réunion in France, Madagascar, Malawi, Mauritius, Mozambique, Seychelles, South Africa and the United Republic of Tanzania. Forecasters considered strengthening El Niño conditions alongside the Indian Ocean Dipole, which is moving from neutral towards a positive phase, and the Subtropical Indian Ocean Dipole in the southern basin, which is moving from positive towards neutral. Together, these climate drivers underpin a forecast with significant implications for agriculture, food security, water resources, health and coastal economies.