Fig. 1

Occurrence years and locations of 224 epidemics as well as disasters owing to anomalous temperatures and irregular precipitations in China between 1 and 1911 CE. a There are 9 solar minimums, low solar activities (LSA; blue bars), and 8 high solar activities (HSA; red bars) during the 1–1911 CE. Years of the epidemic (cross symbols) as well as disasters due to cold (star symbols), hot (square symbols), precipitations (diamond symbols), and droughts (triangle symbols) are denoted. Nine LSA periods: 107–203 CE (second-century minimum), 332–365 CE (fourth-century minimum), 462–526 CE (fifth-century minimum), 580–820 CE (Medieval minimum), 980–1070 CE (Oort minimum), 1280–1350 CE (Wolf minimum), 1410–1590 CE (Sporer minimum), 1645–1715 CE (Maunder minimum) and 1795–1825 CE (Dalton minimum). Red and blue denote HSA and LSA periods, respectively. b The epidemic locations are defined using the 22 current provinces, and subdivided into either northern versus southern area by the climate boundary of the Qinling–Huaihe Line (dark brown curve) at about 33° N or coastal (black characters/bars) versus inland provinces (gray characters/bars). The top two provinces of epidemic occurrences in costal (black dashed ecliptics) and inland (red dashed ecliptics) areas are denoted