Abstract

Weather and climate shape water availability, economic activity, public policy and biodiversity, and extreme events such as droughts, heat waves and floods are becoming more frequent. Using Chile's 2010–2015 megadrought as a starting point, this article explains why long, robust and reliable observational records are essential, both as input to climate models that separate human-caused trends from natural variability and for early warning of extreme events. It traces the history of meteorological monitoring networks, from telegraph-based observation exchange and the creation of the World Meteorological Organization to radiosondes, ozonesondes and satellite data such as TRMM and GPM, which are especially important in the data-sparse Southern Hemisphere. It describes Chile's current observing systems and their gaps, including the lack of a weather radar, and the technical and economic demands of quality control and data availability. It also covers the modernization of WMO systems (WIGOS), GEO/GEOSS and Copernicus, and the shift from data catalogs to web services, illustrated by CR2's Explorador Climático. The article closes by calling for greater investment in instrumentation, research, human capacity and institutional arrangements for climate observation in Chile.