Abstract Motivated by an observed asymmetry in boundary layer convergence lines (BLCLs) between the Kubuqi and Ulan Buh desert borders of the Hetao Oasis in northern China, this work aims to document the differences in BLCL frequency and convective initiation and their potential drivers. Using radar, surface Automatic Weather Station, and reanalysis data in June–August from 2012 to 2022, we found that the Kubuqi border had more frequent, earlier‐forming, and more convective BLCLs, whereas the Ulan Buh border had fewer, shorter‐lived, and more tortuous ones. These contrasts were associated with sharper vegetation and thermal gradients, higher Bowen ratio, and a more favorable background wind on the Kubuqi side. Our findings demonstrate that BLCL behavior is highly sensitive to surface, flow, and terrain heterogeneity, even around a single oasis.