This study provides a comprehensive climatology of summer subtropical anticyclones (SAs) over Southwest Asia using daily ERA-Interim geopotential height data (1990–2019) across six pressure levels (900–100 hPa). Anticyclones were identified on 2760 summer days using combined objective and subjective methods, enabling a multi-level assessment of their frequency, spatial organization, preferred locations, vertical structure, seasonal evolution, and long-term variability. SAs are found throughout the atmospheric column, with maximum frequencies in the mid-troposphere and minimum occurrences near the surface. Distinct spatial modes emerge at different levels—bimodal at 500 hPa, trimodal at 700 hPa, and quadrimodal at 100–200 hPa—revealing finer spatial complexity than earlier climatologies. A key finding is a pronounced vertical seesaw pattern in seasonal occurrence: lower-tropospheric anticyclones peak in June but decline sharply in July, while mid- and upper-tropospheric anticyclones intensify. This indicates a coordinated vertical redistribution of anticyclonic activity during summer. Interlevel relationships exhibit strong coherence in the upper troposphere, whereas weaker correlations between adjacent lower and mid-tropospheric levels suggest level-dependent formation mechanisms and vertical tilt. Regionally, the study refines the characteristics of the Turkmenistan, Zagros, and Arabian anticyclones, highlighting the vertical continuity of the Arabian anticyclone and its sensitivity to surface thermal forcing. Long-term analysis reveals no significant meridional shifts but shows a notable increase in anticyclone frequency at 700 hPa, likely linked to recent warming over the Arabian Peninsula. Overall, the findings demonstrate the dynamical complexity of SAs across Southwest Asia and provide an updated framework for understanding their variability and climate relevance.