The influence of the diurnal cycle on spatial scaling properties of Amazonian rainfall fields is investigated using data gathered during the January–February 1999 Wet Season Atmospheric Meso‐scale Campaign in the state of Rondonia (Brazil, SW Amazonia). Most intense precipitation events with large spatial coverage occur during early afternoon. Amplitudes of average and maximum intensity diurnal cycles are higher during the easterly than during the westerly atmospheric regime. The diurnal cycle of average rainfall occupancy exhibits a significantly larger amplitude during the westerly regime. Storms exhibit power law Fourier spectra, E ( k ) = ck − β , with two scaling regimes characterized by different scaling exponents ( β 1 and β 2 ), separated at a critical distance, which depends on the spatial extent of rainfall organization. Inversely correlated diurnal cycles for β 1 and β 2 reflect rainfall organization patterns at different spatial scales through the 24‐h period. The break occurs at smaller (larger) spatial scales during the morning (afternoon‐evening). Average values of c and β exhibit inversely related diurnal cycles, and different behavior during either atmospheric regime. Order‐ q statistical moments indicate multiscaling of rainfall fields. Departures from simple scaling are also driven by the diurnal cycle, reflecting differences in convective activity and the spatial organization of rainfall throughout the 24‐h cycle. Departures from simple scaling are dependent on the moment order q . Clear‐cut differences between the estimated order‐ q statistical moments appear during both atmospheric regimes. These results shed light toward linking physical processes with statistics in Amazonian storms.