Neutron noise has gained a lot of attention during the last years due to its increasing trend that has been observed in German KWU design pressurized water reactors (PWR) in many European countries. Plant data coming from a Swiss KWU reactor are analyzed in this paper, and the neutron noise phenomenology is extensively discussed and compared against other characteristic examples of KWU PWRs in Europe. Results of this analysis show that, the east-core region exhibits considerably higher neutron noise levels at all axial elevations compared to the other azimuthal core-locations. In addition, it has been observed a slight swift of higher noise amplitudes from core-top to core-bottom axial level, as the burnup increases. Moreover, it has been found an out-of-phase relationship of neutron detector signals between the two halves of the core. These findings are compared against simulation results obtained by the transient nodal code SIMULATE-3K for investigating the validity of the main assumptions that are believed to cause the neutron noise increasing trend. Simulation results indicate that the combination of fuel assembly lateral vibrations and coolant inlet temperature fluctuation can justify, at some extend, the measured neutron noise phenomenology.