Why China’s Heavy Rain Came Early and Strong in May 2026
China is experiencing one of its most intense early-season rainfall events in recent memory, with record-breaking precipitation sweeping across 14 provinces since mid-May. The national average precipitation from April 1 to May 22 reached 110.1 mm — 18.6% above the long-term average, according to Sun Mingyang, an engineer at the National Climate Center. As reported by People’s Daily, the extreme weather has triggered landslides, evacuations, and emergency responses across multiple regions.
The Scale of the Crisis
From May 15 to 20, a large-scale heavy rainfall event affected provinces spanning central and eastern China. The numbers are staggering: 492 meteorological stations recorded daily precipitation exceeding historical extremes, 448 stations broke hourly records, and 76 national-level stations shattered spring seasonal records.
Guangxi’s Fangchenggang recorded 1,186 mm of rainfall during the May 15–20 period — the highest in the country. The human toll has been severe. In Shimen County, Hunan Province, heavy rainfall caused six deaths and left 10 missing as of May 21, with over 100,000 people affected and more than 31,000 evacuated. In Guiding County, Guizhou Province, four deaths and five missing persons were reported. Guangdong Province evacuated 5,533 people from dangerous areas, while Shimen County set up 22 temporary shelters for over 18,000 evacuees.
By May 26, five rivers had exceeded warning levels — Hubei’s Fushui River and its tributaries Yunshui and Huanshui, Jiangxi’s Le’an River, and Henan’s Huanghe River — with the maximum exceedance reaching 3.56 meters, according to CCTV News.
Emergency Response
The Ministry of Water Resources activated a Level IV flood defense emergency response for seven provinces — Jiangxi, Hubei, Hunan, Guangdong, Guangxi, Guizhou, and Hainan. The National Disaster Prevention and Mitigation Committee also activated a Level IV disaster relief emergency response for Guizhou. On May 24, the Ministry of Water Resources and China Meteorological Administration jointly issued the year’s first red mountain flood disaster meteorological warning.
Why the Rain Came So Early and Strong
Meteorologists point to five converging factors behind this extreme weather event.
The Western Pacific Subtropical High was positioned significantly further west and north than normal. By mid-May, its northern boundary reached 27°N — equivalent to the climatological position normally seen in June. Its western flank transported warm, moist air from tropical oceans deep into inland areas.
The South China Sea Summer Monsoon strengthened markedly since mid-May, carrying abundant warm-moist water vapor from the tropical Indian Ocean and South China Sea to central and eastern China. As Sheng Jie, Chief Forecaster at the Central Meteorological Observatory, explained, this provided “abundant moisture conditions for heavy precipitation.”
A blocking high over the Japan Sea created strong easterly winds that transported moisture from the mid-latitude Pacific westward. Meanwhile, a deep trough over Lake Baikal allowed cold air to frequently move southward, converging with tropical airflows.
The “train effect” — where multiple convective cloud clusters pass over the same areas sequentially like train cars — led to extreme accumulation of precipitation in localized areas, particularly in South China’s warm-sector rainstorms, as Sina News reported.
Global warming and El Niño provide the longer-term climatic backdrop. The equatorial central and eastern Pacific entered an El Niño state in May 2026, strengthening the Western Pacific Subtropical High. Chen Lijuan, Chief Forecaster at the National Climate Center, noted that while El Niño creates favorable conditions for increased precipitation, actual weather characteristics exhibit diversity and complexity.
A Changing Climate Context
Since 2020, while spring cumulative precipitation south of the Yangtze River has not significantly increased, the number of extreme precipitation days and their intensity have both markedly risen. The 2016 super El Niño year serves as a reference — that May saw seven heavy rainfall events south of the Yangtze, but with a different regional distribution than 2026.
Experts caution that the current El Niño, while expected to be medium-to-strong, should not be prematurely labeled a “super El Niño.” International models disagree on its exact trajectory, with onset predictions ranging from April to September.
What’s Next
The rain belt entered its strongest phase on May 26, affecting the Sichuan Basin, southern North China, and the Huang-Huai, Jianghuai, Jianghan, and northern Jiangnan regions. Forecasts suggest the rain will weaken and move south between May 28 and 31. However, with El Niño expected to persist through the end of the year, China may face an extended and challenging flood season ahead.