Spikelet sterility (blanking) causes large economic losses to rice farmers in Chile. The most common varieties are susceptible to low air and water temperatures during pollen formation and flowering, which is the main responsible for the large year to year variation observed in terms of blanking and, therefore, of grain yield. The present work had for objective to study the spatial variability of spikelet sterility within two rice fields, during two consecutive seasons, and relate it to water and air temperature as well as soil properties within the field. Two fields of 10 and 20 ha, respectively were studied. A network of 24 temperature sensors, with their corresponding loggers, was deployed within both fields using a systematic non-aligned design, with the help of a GPS and GIS program. Air, at canopy level, and water temperature were measured at 1-hr intervals during the growing seasons. At the same positions, soil chemical properties were measured before planting. At harvest, grain yield and spikelet sterility were determined. Resulted showed a large spatial variability in terms of spikelet sterility within the field in both seasons which related to water and air temperature as well as to their differences. Significant differences in blanking were observed between the evaluated seasons.