Accurate rainfall monitoring is fundamental for hydrological modeling and flood-risk management, yet the spatial density of official rain-gauge networks remains insufficient to capture short-range variability, especially in urban areas. The growing availability of crowdsourced Personal Weather Stations (PWSs) provides an opportunity to increase the density of rainfall observations at minimal cost. This study evaluates the reliability of citizen-owned PWSs across eleven Italian cities and investigates their integration with Official Weather Stations (OWSs) to enhance rainfall observation density in Rome and Turin, validated against radar-derived accumulations. Rainfall data from Netatmo PWSs (5-minute resolution) and regional OWS networks (10- to 30-minute resolution) were collected and aggregated to hourly totals to ensure temporal consistency between datasets.