Post–harvest losses (PHL) are particularly critical for developing countries. This is especially evident in Sub-Saharan (SSA) countries, where PHL are estimated to be about 37% of the total food production. Climate is a core determinant of cereal losses, as biodeterioration factors are sensitive to the temperature and humidity. In this paper we analyse to what extent climatic conditions affect PHL. The analysis considers Sub-Saharan countries and focuses on maize production over the period 2000-2020 period. Data on PHL are taken from APHLIS (African Postharvest Losses Information System), which represents a network of cereals and grain experts in SSA countries. Data collected by APHLIS are aimed at improving existing aggregated data on PHL (e.g. FAO data). PHL data quantify the percentage loss for each phase of the post-harvest chain. APHLIS has some unique characteristics, as it provides PHL at the province (Administrative 1 - ADM1) level over time. The main results of our analysis suggest that humidity is the most relevant determinant of PHL in this region. Our results are relevant, especially if we consider the future instability of the climate in this area.