Recent work shows that during the most prominent climate anomalies during the last millennium, the Medieval Climate Anomaly (ca. 950–1250) and the Little Ice Age (ca. 1450–1850), the South American monsoon system (SAMS) was drier and wetter, respectively. We investigate if this variability in the SAMS is reproduced in the latest set of climate simulations that cover these periods. Despite weak forcing, through analysis of the large-scale circulation we find this signal in the models.