Accelerated dry-wet extremes in China compress recovery windows while impeding economic growth

Climate change-driven dual heatwave-driven drought-wet extremes (DHDWEs)—characterized by abrupt drought-flood transitions under heatwaves—pose growing threats to urban sustainability. Analyzing 334 Chinese cities (1980–2023), we identified newly rising DHDWE frequency (0.34 ± 0.09 events yr−1) and intensity (0.08 ± 0.04 units yr−1), with distinct north-south spatial divergence. We introduced a novel “time tightness” metric to indicate the relative time available for recovery or response between the two extreme phases of a DHDWE, revealing a dangerous downward trend. Panel model analysis shows that DHDWEs cause nonlinear economic losses, with a potential early-warning threshold emerging when time tightness falls below 0.33. Projections under SSP585 suggest DHDWE frequency will surge by 270 ± 120% by 2100, further compressing recovery windows. We therefore propose a Threshold-Alert, Window-Action framework that uses empirical timing thresholds to guide risk prioritization and earlier preparedness, supporting proactive adaptation for cities facing compressed recovery windows and rising economic risk.