<p>Concurrent droughts occur when multiple drought types coexist across space and time, often resulting in greater severity and impacts than single-type droughts. Accurate identification and monitoring of such events and assessing their impacts are crucial but remain limited, as most existing indices rely on fixed time scales of single drought indicators, seldom account for time-lag effects and generally operate at relatively coarse spatial resolutions; This study developed a copula-based Concurrent Drought Index (CCDI) using a vine copula model to construct an optimal joint probability distribution among meteorological, soil, and groundwater droughts while accounting for their lag times and cumulative effects, the CCDI was then applied to Northern China to identify concurrent drought events, assess monitoring performance, and analyze spatial and temporal drought characteristics. The results showed that: (1) Notable spatial heterogeneity exists in the lag times among the three drought type; the Clayton copula performing best in most regions. (2) CCDI effectively identified concurrent droughts, with results consistent with historical records across the North China Plain, Loess Plateau, and Northeast China, and revealed a significant intensification and expansion of concurrent droughts across Northern China during the past decade. (3) High-frequency and severe drought areas were mainly distributed in the Northeast China Plain, central and western Inner Mongolia, and northern North China Plain, which were also prominent grain and forage production bases in China, emphasizing the need for region-specific drought mitigation strategies.</p>