Abstract Atmospheric stability quantifies the resistance of the atmosphere to vertical displacement and turbulent mixing. Under Arctic warming, the atmosphere has become more dynamically active, which may influence atmospheric stability. Using ERA5 reanalysis, we show that the decrease in Arctic atmospheric stability has been amplified relative to the global mean over the past 40 years, occurring primarily during polar night and concentrated over the Barents–Kara Seas and the Chukchi Sea. Vertically, interannual destabilization trends over the Barents Kara Seas extend up to 850 hPa, whereas those over the Chukchi Sea remain largely confined below 900 hPa. Furthermore, the pan‐Arctic mean atmospheric destabilization intensity and vertical extent exhibit interannual variability. Destabilization intensity strengthens progressively and peaks in the mid‐2010s, while the destabilized layer expands upward to about 700 hPa during polar night. Meanwhile, the linkage between destabilization intensity and Arctic warming is strong before 2012 but weakens thereafter.