The microbes found in topsoil are a vital part of the Earth’s ecology. While several recent studies have explored these microbiomes on a global scale, their data on sub-Saharan Africa was sparse, despite the looming threat of climate change to the region. To close this gap, researchers recently examined the microbial ecology of 810 sites across 9 sub-Saharan African countries. The topsoil microbiomes were shaped by a broad range of environmental factors, particularly pH, precipitation, and temperature, and each nation had a quantifiably distinct topsoil microbiome. Computer models based on the data also predicted how country-specific microbiomes might respond to climate change. In Kenya, for example, higher temperatures and lower rainfall could diminish microbial diversity, whereas in Benin, the predicted increase in precipitation is likely to boost fungal biodiversity. These results represent the most extensive biogeographical survey of sub-Saharan topsoil microbiomes to date, and given that many economies in this region depend on rain-fed agriculture, this study provides crucial information to support their climate change response.