Scientists have found that sea surface temperatures in the Atlantic and Indian Oceans could help predict malaria outbreaks in Malawi months in advance, offering a new approach to early warning systems for one of the country’s most widespread infectious diseases.
The study published in Communications Medicine, found that changes in ocean temperatures influence soil moisture in Malawi, which in turn affects mosquito breeding conditions and malaria transmission. Researchers identified soil moisture as the strongest environmental link connecting distant ocean temperature patterns to local malaria risk.
Malaria remains a major public health challenge in Malawi, accounting for nearly 7 million morbidity cases and 36% of outpatient visits in 2025. Researchers say forecasting outbreaks in advance could help health authorities prepare resources and strengthen disease control efforts.
The research team analysed 19 years of district level malaria data alongside satellite observations of sea surface temperatures, rainfall and soil moisture. They found that warmer than average temperatures in the tropical Atlantic Ocean increased rainfall and soil moisture in Malawi, creating favourable conditions for mosquito breeding and raising malaria risk.
In contrast, warmer temperatures in the central Indian Ocean were linked to increased evaporation, which dried out soils despite some additional rainfall. These drier conditions were generally less suitable for mosquito breeding, reducing the likelihood of malaria transmission.
The study found that soil moisture was a better predictor of malaria risk than rainfall alone because it reflects how much water remains on the ground after rainfall and evaporation. Standing water is essential for the development of Anopheles mosquitoes, which transmit the malaria parasite.
Researchers said sea surface temperatures change more gradually than rainfall or daily weather, making them useful for developing early warning systems capable of predicting malaria risk several months in advance.
The team also examined future climate scenarios and projected that Malawi could experience a gradual decline in average soil moisture by the end of the century. However, they cautioned that drier conditions would not necessarily reduce malaria cases, as transmission could shift to different regions rather than disappear.
The researchers noted that climate is only one factor influencing malaria transmission. Housing conditions, access to healthcare, socioeconomic factors and public health interventions also play important roles and would need to be considered in any future forecasting system.
They concluded that combining climate indicators such as ocean temperatures and soil moisture with health data could improve malaria preparedness and help authorities respond before outbreaks occur.