Bulk apparent soil electrical conductivity (ECa) is the most widely used soil sensing modality in precision agriculture. Soil ECa relates to multiple soil properties, including clay content (i.e., texture) and salt content (i.e., salinity). However, calibrations of ECa to soil properties are not temporally stable, due in large part to soil moisture differences between measurement dates. Therefore, the objective of this research was to investigate the effects of temporal soil moisture variations on ECa data collected within a field with highly varying soil texture and a growing cotton crop. A variable-rate irrigation experiment imposed additional soil water content (WC) variability. Data were collected with an electromagnetic induction ECa sensor four times within the 2017 growing season, and a fifth time pre-planting. Profile WC to approximately 68 cm depth was measured using time-domain reflectometry (TDR) sensors within season and gravimetrically pre-planting. Regressions estimating WC from ECa data were developed and used to map spatially variable WC. Changes in ECa-estimated WC between measurement dates corresponded reasonably well with a mapped water balance. These results are a step toward the overall goals of this research, which are to estimate WC from ECa and also to standardize ECa-based estimates of other soil properties for WC variation. Such standardized estimates would be beneficial, for example, to more effectively translate ECa data into texture information that could be used for establishing variable-rate irrigation strategies.