This review discusses the impacts of climate variability and extreme weather events on biological and food systems, particularly in the developing world. It highlights that while most climate change studies focus on changes in average climate, the effects of climate variability and extreme events are often underestimated. The review presents new analysis suggesting that increased climate variability may lead to greater food insecurity in the future. It considers how people adapt to climate variability and extreme events and identifies key knowledge and data gaps, including the interactions of different climatic stresses on plant growth and the impacts of climate variability on pests, weeds, and diseases. The review emphasizes the need for research that can provide actionable answers for decision-makers and the importance of investing in climate and environmental monitoring. It also discusses the impacts of climate variability on food systems, health, and nutrition, noting that climate variability can affect food availability, access, and nutrition, leading to increased undernutrition and stunting. The review concludes that vulnerability to climate change is influenced by socioeconomic and political factors, and that addressing climate variability and extreme events requires a comprehensive approach that includes improving adaptive capacity, enhancing resilience, and integrating indigenous knowledge into formal monitoring systems. The review also highlights the need for further research in areas such as the effects of climate variability on food systems, the role of indigenous knowledge, and the development of robust adaptation strategies.This review discusses the impacts of climate variability and extreme weather events on biological and food systems, particularly in the developing world. It highlights that while most climate change studies focus on changes in average climate, the effects of climate variability and extreme events are often underestimated. The review presents new analysis suggesting that increased climate variability may lead to greater food insecurity in the future. It considers how people adapt to climate variability and extreme events and identifies key knowledge and data gaps, including the interactions of different climatic stresses on plant growth and the impacts of climate variability on pests, weeds, and diseases. The review emphasizes the need for research that can provide actionable answers for decision-makers and the importance of investing in climate and environmental monitoring. It also discusses the impacts of climate variability on food systems, health, and nutrition, noting that climate variability can affect food availability, access, and nutrition, leading to increased undernutrition and stunting. The review concludes that vulnerability to climate change is influenced by socioeconomic and political factors, and that addressing climate variability and extreme events requires a comprehensive approach that includes improving adaptive capacity, enhancing resilience, and integrating indigenous knowledge into formal monitoring systems. The review also highlights the need for further research in areas such as the effects of climate variability on food systems, the role of indigenous knowledge, and the development of robust adaptation strategies.