Roadmap to discover, transcribe, and analyse early 20th Century weather observations from Singapore, West Malaysia, and northern Sumatra

Global climate datasets portray an asymmetrical collection of historical observations, a selected few regions and time-periods contribute more than others. For example, observations from Western Europe and North America in the 20th Century are more numerous than all other regions of the globe combined over the same period. Estimation of return period (probability) of any extreme weather events depends on the observation of similar events in the past. Also, observations of past extreme weather events are necessary to understand the severity and scope of future extreme events. Regions newly liberated from colonisation since the end of World War II suffer from much sparser data collection. Here, we present a comprehensive plan to discover, transcribe, and analyse historical weather observations from Singapore, West Malaysia, and northern Sumatra from 1900 to 1960s.Our primary objective is to construct a long time-series of historical instrumental meteorological data and understand extreme climate-induced events, their impacts and associated societal responses in the region. To do so, we utilise varied and diverse sources of information such as weather journals-records, missionary documents and newspapers from the study period. We transform qualitative descriptions of extreme weather conditions into continuous quantitative ordinal-scale climate indices using novel transfer functions for historical climatological data. Finally, these indices will be used to assess resilience of society and local economy to the shocks of prolonged adverse weather events, helping policy makers calibrate policy interventions in the event of extreme weather induced disasters