The 3rd phase of the Centre of Excellence in Simulation of Weather and Climate in Europe, ESiWACE3, focuses on supporting the weather and climate modelling community to reach a higher readiness level regarding exascale supercomputing and foster knowledge transfer between the different Earth System modelling centres and teams across Europe. At this aim, climate modelling groups have teamed up with High-Performance Computing (HPC) centres and partners from the technology industry to improve all aspects of the weather and climate modelling workflow.