This dataset presents a 31-year IFS-FESOM coupled climate model simulation using constant 1950 radiative forcing, based on CMIP6 standards. It is part of the official coupled spin-up for EERIE phase 1 simulation and reaches a steady state after the first 10 years. The simulation features high-resolution grids: approximately 9 km for the atmospheric component (IFS) and 5 km for the ocean component (FESOM). The atmospheric component uses ECMWF IFS cycle 48R1, while the ocean model employs FESOM2.5 with an NG5 grid comprising about 7.5 million surface nodes. The dataset includes high-priority variables in both native high-resolution grids and interpolated to a 0.25-degree regular grid. Vertically, the atmosphere is resolved with 137 levels (output provided at 23 pressure levels), and the ocean with 70 depth levels. Prior to the main simulation, the ocean model underwent a 5-year stand-alone spin-up using EN4 boundary conditions. This high-resolution simulation effectively resolves mesoscale eddies in midlatitude oceans and simulates tropical instability waves, with a potential to offer insights on their role in our climate system. The EERIE version identifier for this dataset is v20240304.