evidence: The present study conducts an updated detection and attribution analysis of the observed Arctic SIA changes across all months over the 1979–2019 period by comparing three satellite observations with the CMIP6 multi-model simulations. Previous attribution studies were mostly based on sea ice extent which is defined as the total area of all grid cells with at least 15% sea ice concentration and hence is strongly grid dependent1. Here we use SIA which is defined as the actual area covered with sea ice and is more appropriate for comparison with satellite observations than sea ice extent20, having a smaller observed uncertainty than sea ice extent21. The Arctic sea ice has been melting in all months22,23,24 but most previous studies have focused on September when the largest change occurred. Considering all calendar months and utilizing individual forcing simulations, this study finds that the response to GHG increases is detected throughout the year, explaining most of the observed SIA reduction. Further, based on the quantified GHG contribution to the observed Arctic SIA reduction, the future timing of the ice-free Arctic Ocean is projected under the different Shared Socioeconomic Pathway (SSP) emission scenarios. [...] Mahlstein, I. & Knutti, R. September Arctic sea ice predicted to disappear near 2°C global warming above present. J. Geophys. Res. Atmos.117, D06104 (2012).