The timing of sea ice melt onset (MO) strongly influences the length of the melt season and the subsequent summer ice evolution of Arctic sea ice. However, the atmospheric mechanisms governing the pronounced interannual and regional variability in MO remain incompletely understood. Here, we investigate the atmospheric contribution to the spatiotemporal variability of MO dates across the Arctic sea ice during spring (April–June) over 1980–2017. Using passive microwave satellite-derived MO dates and ERA5 reanalysis, we identify regions of extreme positive surface energy budget (SEB) anomalies (SEB events) as markers of episodic atmospheric influence and relate their occurrence and airmass origin to locally anomalous MO timings in a pixel-based framework. Very early MO occurs preferentially in the Beaufort, Kara, and Barents Seas and is associated with strongly enhanced frequency of SEB events during the 24 days preceding melt, with peak occurrence both near the melt date and about 3 weeks earlier. Earlier melt is further characterized by larger-than-usual anomalies in downward longwave and turbulent fluxes and predominantly associated with SEB events of Pacific and Atlantic airmass origin. In contrast, very late MO is located more widespread across the eastern Arctic Ocean and coincides with a significant absence of SEB events before melt, weaker downward longwave fluxes, positive downward shortwave anomalies under clear-sky conditions, and continental airmass inflows. These results demonstrate that synoptic-scale atmospheric processes are a key driver of regional MO variability and highlight the need for improved representation of springtime atmosphere–ice interactions in climate models to properly capture the seasonal transition in the Arctic.