Wang F.Lei G.Muangsong C.Cai B.Li M.Fang K.Pumijumnong N.Chatwatthana R.Panthi S.Mahidol University2026-02-062026-02-062026-02-01Global and Planetary Change Vol.257 (2026)09218181https://repository.li.mahidol.ac.th/handle/123456789/114450The East Asian Summer Monsoon (EASM) precipitation in southeastern (SE) China has intraseasonal evolution, unique characteristics, and complex drivers. Within the EASM, April precipitation plays a crucial role in the first rainy season (FRS) precipitation. Accurately quantifying the long-term temporal variability of FRS precipitation is essential for enhancing monthly and seasonal precipitation forecasts. This study presented the hitherto longest tree-ring δ¹⁸O chronologies (LSMδ¹⁸O) of Cryptomeria fortune trees spanning 201 years (1816–2016 CE) from Fujian province in SE China. The LSMδ¹⁸O chronology showed the strongest negative correlation with monthly precipitation in April ( r = −0.59, p < 0.001) for the calibration period 1951–2016 CE, indicating a strong association between the tree-ring δ¹⁸O signature and FRS precipitation variability. This relationship enabled the first reconstruction of April precipitation (reconstructed PRE<inf>Apr</inf>) in SE China for the period 1856–2016 CE. A total of 30 % (48 events) of precipitation anomalies were observed in the reconstruction. The low-PRE<inf>Apr</inf> anomalies were identified, for example, in 1875, 1895, 1902, 1987, 1998, and 2004 CE. Reconstrued PRE<inf>Apr</inf> revealed spectral peaks of 2–7 years high-frequency periodicities associated with El Niño–Southern Oscillation activities due to higher sea surface temperature variation at the tropical Pacific Ocean. The reconstructed PRE<inf>Apr</inf> effectively captured the synchronous precipitation shifts across SE China and the western Pacific domain, indicating an anomalous declining trend in the large-scale precipitation changes since the 1950s CE. The seasonal extreme precipitation events associated with rising Northern Hemisphere temperatures have become more frequent and severe in SE China under a warming climate.Earth and Planetary SciencesEnvironmental ScienceArticleSCOPUS10.1016/j.gloplacha.2025.1052492-s2.0-105025093669