Year-round moorings (1990 to 2004) illustrate interannual variability of Bering Strait volume, freshwater and heat fluxes, which affect Arctic systems including sea-ice. Fluxes are lowest in 2001 and increase to 2004. Whilst 2004 freshwater and volume fluxes match previous maxima (1998), the 2004 heat flux is the highest recorded, partly due to ∼0.5°C warmer temperatures since 2002. The Alaskan Coastal Current, contributing about 1/3rd of the heat and of the freshwater fluxes, also shows strong warming and freshening between 2002 and 2004. The increased Bering Strait heat input between 2001 and 2004 (>2×1020 J) could melt 640,000 km2 of 1 m thick ice; the 3-year freshwater increase (∼800 km3) is about of annual Arctic river run-off. Weaker southward winds likely explain the increased volume flux (∼0.7 to ∼1 Sv), causing ∼80% of the freshwater and ∼50% of the heat flux increases.