Water use (WU) and water use efficiency (WUE) of crops are affected by local weather conditions and available soil water. The objectives of this study were to determine the impact of weather variability and soil moisture deficit on WU and WUE of sweet corn. An experiment was conducted in 2006 at the Bledsoe Research Farm of the University of Georgia in Pike County, Georgia, USA, in a soil characterized as a Cecil sandy clay loam. Sweet corn (sh2 type) was planted using a simple one-way randomized complete block design and four replicates during three sowing dates. The first sowing date, conducted on March 27, consisted of two experiments; one rainfed and one irrigated. The second and third sowing dates, conducted on April 10 and April 25, were both irrigated. Irrigation was applied with a linear sprinkler irrigation system. For each sowing date, the soil moisture was monitored in each replicate twice per week using a PR2 at six fixed depths (10, 20, 30, 40, 60, and 100 cm). Rainfall and irrigation were recorded with rain gauges installed in the experimental area; other weather variables were recorded with an automatic weather station located near the experiment. Growth analysis data were collected every two weeks. At final harvest yield and yield components were obtained from 3-m row from each replicate. WU was calculated as the sum of crop's daily evapotranspiration (ETa) and WUE was calculated as the ratio of the crop's aboveground biomass and ETa. As a measure of the crop's moisture stress, potential soil moisture deficit was also calculated. Differences within sowing dates were evaluated using a single degree freedom contrast, simple regressions, and the LSD test. WU and WUE differed significantly between sowing dates and between rainfed and irrigated conditions and WUE increased with soil moisture deficit.