Land-sea breezes are closely connected with the diurnal cycle in rainfall in the Indo-Pacific Maritime Continent (MC). Most studies on land-sea breezes in the MC have so far been based on numerical simulations. In this study, observations from coastal stations and satellites are used to document the connection between land-sea breezes and the diurnal cycle in rainfall. The results illustrate the extent to which they are synchronized and the extent to which they are independent of each other. Metrics for this connection include the time of wind direction switches vs. the diurnal rainfall onset, seasonal dependence of the diurnal evolution in both wind and rainfall, etc. Observations are compared to high-resolution numerical simulations to assess the capability of the state-of-the-art cloud-allowing models to accurately reproduce the observed connection between land-sea breezes and the diurnal cycle in rainfall.