This research presents analyses of ten model simulations to investigate the interannual variability of temperature and precipitation during the Last Millennium and the possible causes. It is revealed that the interannual temperature and precipitation variability is generally larger at high latitudes and in tropical monsoon regions respectively, both with seasonal magnitudes larger than the annual levels. The zonal mean of interannual temperature and precipitation variability exhibits significant multi-decadal-scale changes, while the long-term trends are indistinctive. Temperature variability matches well with volcanic eruptions, with a maximum correlation coefficient of 0.23 (0.46) for the median estimate (individual models) at some latitudes, and the volcanic influence mainly concentrates in the midlatitudes where the temperature variability is small, indicating a possible driver for the interannual scale climate change. 

Time-latitude plots of the zonally averaged interannual variability of the simulated annual temperature (units: K), with the temporal mean subtracted from each year along latitudes, and the correlation coefficients between the interannual variability and the corresponding aerosol optical depth and total solar irradiance reconstructions.