A very strong El Niño event is building in the Pacific, and Ghana is expected to feel its effects in stages. The Ghana Meteorological Agency (GMet) has published a 31-page advisory outlining the potential impacts. According to GMet, Ghana can expect a hotter, drier dry season from late November, the most dangerous heat of the year between February and April, a 2027 rainy season that could disappoint or overflow, and a test for hydropower that arrives only in 2028.
El Niño is the warm phase of a natural cycle in the central and eastern equatorial Pacific. When the ocean warms well above normal, it shifts thunderstorms, winds, and rainfall across the tropics, and the effects reach West Africa. The National Oceanic and Atmospheric Administration (NOAA) declared El Niño conditions in June, with an official reading of +1.7°C above normal in July-September. NOAA gives a 96% chance that the event reaches very strong intensity, +2.0°C or more, in November-January.
Ghana has experienced four very strong El Niño events since 1980, with uneven results. Some of the most damaging climate shocks occurred in years without an El Niño, while several disasters that coincided with one have not been attributed to it. Past El Niño events have shown that impacts arrive together, straining food crops, food prices, hydropower, and public health simultaneously. Notable events include the 1981-83 drought, the 1997/98 power crisis, and the 2015/16 late rains and low lake levels.
GMet's advisory sets out what to expect, period by period, from now until the Volta basin's inflow season ends in October 2027. The dry season outlook forecasts below-normal rain across much of Ghana and warmer-than-average temperatures in most places, with a hotter, drier dry season from late November. Some areas are still expected to see above-normal rain, and localized heavy downpours remain possible in the south.
February to April 2027 is expected to be the hottest stretch of the year in northern Ghana, with tropical temperatures tending to peak during this period. Heat stress is expected to be particularly high, especially in the north. The harmattan, which typically runs from late November to March, may also be intensified due to dry ground and vegetation.
The 2027 rainy season could be disappointing or overflow, depending on the Atlantic Ocean's influence. Ghana's rainfall is governed by the tropical Atlantic as much as by the Pacific, and sea temperatures in the Gulf of Guinea control how much moisture reaches the coast and when the rains begin. El Niño tends to warm the tropical North Atlantic a few months after it peaks, which may pull the rain belt northwards, favoring the Sahel over the coast.
The potential impacts of El Niño on Ghana's power supply are a significant concern, particularly in 2028. The 1997/98 El Niño event led to a power crisis due to reduced rainfall and inflows into Lake Volta. GMet's advisory notes that the strength of an El Niño event does not necessarily match the strength of its impacts, and the agency is cautious about what it does not know. The government and relevant agencies will need to take proactive measures to mitigate the potential effects on power generation and distribution.
Key points
- A very strong El Niño event is expected to impact Ghana's climate, with potential effects on heat, food, health, water, and power into 2028.
- Ghana has experienced uneven impacts from past El Niño events, with some of the most damaging climate shocks occurring in years without an El Niño.
- The 2027 rainy season and 2028 power supply are significant concerns, with potential impacts on food crops, food prices, hydropower, and public health.
