Winter Arctic extreme temperature amplification has exceeded sixfold linked to sea ice loss since 1979

The Arctic is warming rapidly, but the extent to which winter temperature extremes amplify relative to the global mean remains insufficiently quantified. Here we use four reanalysis datasets and large-ensemble simulations from the Polar Amplification Model Intercomparison Project (PAMIP) to assess winter Arctic extreme temperature amplification during 1979–2024 and its connection to sea ice loss. Across the reanalyses, winter Arctic daily mean temperature (T_mean), daily maximum temperature (T_max), daily minimum temperature (T_min) and the coldest daily minimum temperature (TN_n) warm 3.7, 3.8, 3.9 and 4.7 times faster than their global means, respectively. The strongest response occurs over the Barents-Kara seas, where the warming rate of extreme temperature events exceeds six times the global mean. Singular value decomposition identifies a coupled pattern in which sea ice loss and extreme warming co-locate over the Barents-Kara seas. PAMIP experiments further show that prescribed Arctic sea ice loss generates coherent near-surface warming over major ice loss regions. The response is supported by enhanced turbulent heat fluxes, increased water vapor, stronger downward longwave radiation and a robust mid-tropospheric anticyclonic anomaly with subsidence warming. These findings underscore the critical role of sea ice–atmosphere coupling in shaping Arctic extreme temperature amplification and highlight the urgent need for further investigation and adaptive mitigation strategies.