Six decades of ground-based climate monitoring indicate warming and increasing precipitation seasonality and intensity in Yangambi (central Congo basin)

Abstract Meteorological stations are rare in the tropics and satellite products often do not perform optimal. This leads to uncertainty in modelled regional climatic trends and may lead to opposing trends in prediction of future climate. This is particularly problematic for the Congo basin, where station coverage decreased significantly during the last few decades. Therefore, here we present a newly digitised dataset of daily temperature and precipitation from the Yangambi biosphere reserve, covering the period 1960 - 2020 (61 years) and located in the heart of the Congo basin. Our results confirm a long-term increase in temperature and temperature extremes since the 1960s, with strong upward trends since the early 1990s. Our results also indicate a drying trend for the dry season and intensification of the wet season since the early 2000s. Ongoing warming and increasing precipitation seasonality and intensity already has a significant impact on crop yields in Yangambi. This calls for urgent development of climate-smart and dynamic agriculture and agroforestry systems. We conclude that systematic digitization and climate recording in the Congo basin will be critical to improve much-needed gridded benchmark datasets of climatic variables.