In Depth: China’s ‘Rain Belt’ Marches North, Unleashing Floods on Arid Lands

In the closing weeks of 2025, North China experienced exceptionally frequent and intense rainfall, surpassing historical records and expanding the traditional flood season. Major northern cities and regions, including Hohhot in Inner Mongolia and districts in Beijing, recorded unprecedented precipitation levels. Hohhot approached 800 millimeters of annual rain, double its usual amount, while parts of Beijing exceeded 1,000 millimeters, nearly two times the normal average. The flood season started early, lasting from July 5 to September 2—about a month longer than usual—and brought the highest summer rainfall totals to Beijing and Inner Mongolia since records began in 1961. Even after summer ended, autumn continued unusually wet, with Shandong and Henan registering their wettest autumns ever, while neighboring provinces also ranked among their highest. Meanwhile, South China experienced the opposite: a drier-than-average season due to the East Asian monsoon delivering its main rain belt farther north, disproportionately affecting the Yellow and Huai river basins and North China. The human and economic impact was substantial: severe floods in July and August left 217 dead or missing in the north and northwest, and by the year's third quarter, official data showed over 22.7 million affected, 404 fatalities or missing, and losses reaching 165 billion yuan ($23 billion)—the majority in the north [para. 1][para. 2][para. 3][para. 4][para. 5][para. 6][para. 7].

The pattern for 2025 saw the rain belt shift “too far north,” leading to rainfall records in Inner Mongolia, which had not experienced such extremes since systematic record-keeping began. Climate officials noted that the 400-millimeter precipitation line, which typically divides semi-arid and semi-humid zones, appeared to have moved northward significantly in 2025. Experts described the year as “highly abnormal,” with the main rain belt reaching as far as Inner Mongolia, a phenomenon previously unprecedented in modern China’s climate records [para. 8][para. 9][para. 10][para. 11][para. 12][para. 13][para. 14].

Debate persists among climate scientists about whether the recent changes signal a cyclical event or a longer-term shift resulting from climate change. Some believe the anomaly is a product of natural oscillations, while others argue global warming is altering atmospheric behavior, leading to greater rainfall as warmer air holds more moisture. In 2025, the West Pacific subtropical high—a key atmospheric system—influenced this abnormal moisture transport, pushing the rain belt north and acting like a pump. Experts connect the ongoing poleward expansion and intensification of subtropical high-pressure systems to global warming and changes in the Hadley circulation [para. 15][para. 16][para. 17][para. 18][para. 19][para. 20][para. 21][para. 22].

The surge in rainfall presents significant challenges for the traditionally drought-prone north, now vulnerable to both flooding and continued drought cycles. July and August saw around 20 northern rivers overflow, causing unprecedented floods in areas like Gansu and Inner Mongolia. Meanwhile, reduced rainfall in southern China led to drought, notably in the Yangtze basin, which suffered severe shortages in 2022 and again in 2025 when autumn rains failed to materialize. A northward shift of the rain belt may modify agricultural patterns, but can also trigger increased crop damage, lower yields, and expanded pest ranges due to misaligned rainfall timing. Experts caution that the north is entering a volatile cycle of alternating droughts and floods, with more frequent and intense extremes posing ongoing threats to ecosystems, urban and rural infrastructure, and agriculture. This wet phase is expected to persist, with research indicating North China undergoes decadal precipitation cycles, but remains far from the end of the current above-normal period [para. 23][para. 24][para. 25][para. 26][para. 27][para. 28][para. 29][para. 30][para. 31][para. 32][para. 33][para. 34][para. 35].