Reference
Li, M.-Q., Ge, Q.-S., Hao, Z.-X., Zheng, J.-Y. and He, S.-F. 2010. Characteristics of cold-warm variation in the Hetao region and its surrounding areas in China during the past 5000 years. Climate of the Past 6: 475-481.
Description
Li et al. developed a composite temperature history of the Hetao region of China stretching 5000 years back in time from the early 2000s, based on pollen data from Daihai Lake (40°N, 112°E), oxygen isotope data from a salt lake in Yikezhaomeng, Inner Mongolia (39°N, 109°E), and total organic carbon data from Jingbian County (37°N, 108°E). This temperature history indicated, in their words, that "the climate was relatively warm" between 1450 and 1000 calendar years before present (AD 550-1000), which "corresponded to the Medieval Warm Period." And it is clear from their graph of the data that the peak warmth of the MWP was greater than the peak warmth of the CWP, which for this part of China occurred about AD 1800, after which the region began to cool again.