Abstract As sea ice becomes thinner and more fragile, it may affect the Arctic Ocean methane budgets in winter. Using satellite, in situ and reanalysis data, the oceanic emissions of methane over the Chukchi Sea coast from 2003 to 2023 are investigated. In total, 196 methane ventilation days were recorded, contributing to atmospheric methane increases by 15.7 ppb dâ1. Methane ventilation is dominated by sea ice opening and is greatly enhanced by coastal upwellingâinduced mixing. The methane concentration increases by 5.5[3.3, 7.8] ppb dâ1 with every 10% decrease in ice concentration. The average contribution of upwelling is 0.84[â1.1, 2.7] ppb dâ1, with the greatest contribution from warm Atlantic Water (AW). One such AW event can lead to an increase of methane up to 10[â2, 22] ppb. With further ice retreat, upwellingâinduced oceanic methane emissions may occur widely and should be fully considered.