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The Hulun Buir sandy land in northern China is located at the northern limit region of the East Asian summer monsoon (EASM) and is therefore sensitive to the extension of the front of the rainfall belt. Here we report an n-alkane and compound-specific carbon isotope record from the Holocene sediments of Lake Yiheshariwusu in the middle of the Hulun Buir sandy land. The sediments contain a suite of n-alkanes with a strong odd over even carbon number predominance, with the maximum contribution from nC31, which is a typical distribution in grassland regions. The low temperatures in this cold region greatly limit the growth of C4 plants and thus the long-chain n-alkanes in lake sediments are mainly derived from leaf wax lipids of C3 plants growing within the sandy land. In this C3-vegetation-dominated region, the δ13C27–33 value (weighted carbon isotope values of nC27– nC33) are regulated mainly by the physiological and biochemical responses of plants to water stress and are therefore interpreted as a proxy of effective precipitation or humidity. The δ13C27–33 time series shows a trend of gradually decreasing values that suggests an increase in effective precipitation since 8.5 ka (1 ka = 1000 cal yr BP). Relative droughts occurred during the intervals of 6.3–5.5, 4.1–3.6 ka, and during the last 200 years. In addition, the δ13C27–33 time series and comparable paleoenvironmental records from neighboring sites suggest opposite trends of summer monsoon rainfall between northeastern and southeastern China. We suggest that a coupled process between low and high latitudes (the western Pacific Subtropical High and the Okhotsk High) may have played a fundamental role in regulating the shift of the frontal rainfall belt and monsoon rainfall distribution in eastern China during the Holocene.

Seasonal temperature variability over longer timescales could offer new insights into understanding different forcing factors and response processes in the climate system. Here we report an alkenone-based temperature reconstruction for growing season over the past 1600 years from the varved sediment in Lake Sihailongwan, northeastern China. The most notable cold spells occurred during the periods ad 480–860, ad 1260–1300, ad 1510–1570 and ad 1800–1900 with a temperature decrease of about 1°C compared with the 20th century. Based on the historical evidence such as ‘snow or frost in the summertime’ and ‘no ice during the wintertime’, we compile extreme cold summer events and warm winter events over the past 1600 years. The ‘Little Ice Age’ time period experienced more extreme cold summer/warm winter events, while the ‘Medieval Warm Period’ had milder winters. Comparatively, the natural proxy data show a general similar pattern with historical documents at decadal time scales, except for between ad 1620 and 1720. Our results show multidecadal to centennial variations in seasonal temperature, possibly caused by interactions of external natural forcing and atmosphere–ocean circulations.