Various geophysical diagnostics calculated from model output obtained from the Coupled Model Intercomparison Project phase 6 (CMIP6), for pre-industrial control, historical, SSP3-7.0, and SSP5-8.5 simulations of 20 climate models. Diagnostics include monthly-mean sea ice area, extent, and sea ice-edge latitude, annual ocean and atmospheric meridional energy transports, and annual polar-cap averages of ocean heat content, near surface air temperature, and atmospheric vertical heat fluxes. Analogous sea ice diagnostics from passive-microwave observations, and surface temperature diagnostics from atmospheric reanalysis products (CFSR, CFSv2, ERA5, JRA-55, and MERRA-2), are also included.