Precipitation [P: mm] controls forest and woodland dynamics in the southwestern United States (SWUS) by altering soil moisture [theta: mm(3) mm(-3)] availability, but the influence of P on theta is complex, varying across space and time. We evaluated seasonal P and theta relationships at shallow (0-20 cm) and intermediate (50 cm) soil depths for nine semiarid forest and woodland sites (56 total years), which comprised three elevation gradients in the SWUS. We developed time-varying definitions of winter (snow accumulation), spring (moisture recharge), and summer (moisture deficit), and determined how these sites exhibited similar P influence on theta across depths in the soil profile, between seasons, and in seasons with above- and below-average P. Higher elevation sites (>2,800 m) experienced greater winter P, longer springs, and shorter summers compared to lower elevation sites (<2,500 m). Seasons with above- and below-average P reduced elevation-associated differences. theta at 0-20 cm was generally decoupled from theta at 50 cm in seasons with average and below-average P, imparted by differences in spring and summer rainfall versus winter snowfall. Notably, across-season influence of theta (e.g., a season's similarity to subsequent seasons) was high when the first season experienced above- or below-average P, and the subsequent season experienced average P, illustrating an important temporal connection initiated by wet and dry conditions. These results illustrate similarities in P-theta relationships across widely differing ecosystems in the SWUS, and elucidate how these relationships may be altered in a changing climate.