The first half of the 20th century was an era of weathering heights. As the development of powered flight made the free atmosphere militarily and economically relevant, meteorologists encountered new kinds of weather conditions at altitude. Pilots also learned to weather heights, as they struggled to survive in an atmosphere that revealed surprising dangers like squall lines, fog, icing, and turbulence. Aeronautical meteorology evolved out of these encounters, a heterogeneous body of knowledge that included guidelines for routing aircraft, networks for observing the upper air using scientific instruments, and procedures for synthesizing those observations into weather forecasts designed for pilots. As meteorologists worked to make the skies safe for aircraft, they remade their science around the physics of the free atmosphere. The dissertation tracks a small group of Scandinavian meteorologists, the “Bergen School,” who came to be the dominant force in world meteorology by forecasting for Arctic exploration flights, designing airline weather services, and training thousands of military weather officers during World War II. After the war, some of these military meteorologists invented the TV weather report (now the most widely consumed genre of popular science) by combining the narrative of the pre-fight weather briefing with the visual style of comic-illustrated training manuals. The dissertation argues that aeronautical meteorology is representative of what I call the “infrastructural sciences,” a set of organizationally intensive, purposefully invisible, applied sciences. These sciences enable the reliable operation of large technological systems by integrating theory-derived knowledge with routine environmental observation. The dissertation articulates a set of characteristics for identifying and understanding infrastructural science, and then argues that these culturally modest technical practices play a pervasive role in maintaining industrial lifeways. It concludes by noting that while meteorology successfully helped aviation become a reliable, taken-for-granted part of the transportation system, the interests of aviation created a meteorology that centered on the needs of pilots, to the detriment of fields like agricultural climatology.