Chinese Weather Experts Explain Science Behind 'Heat Dome' and Heatwave

Since July 2026, widespread and prolonged heatwaves have impacted Northwest China, southern North China, and parts of the Huanghuai region. Addressing public discussion surrounding 'heat domes,' a chief forecaster at China's National Meteorological Center explained in People's Daily that 'heat dome' is an illustrative popular science term rather than a formal meteorological definition. The expert clarified that the direct driver of the current northern heatwave is a stable high-pressure ridge, which traps sinking air and traps solar radiation near the surface.

Clarifying the meteorological mechanism behind popular terms like 'heat dome' helps the public accurately understand extreme weather phenomena while avoiding conceptual misunderstandings. It also provides a scientific foundation for regional heatstroke prevention, agricultural drought management, and energy grid load planning amid accelerating climate change.

Since July 2026, extensive and persistent high temperatures have swept across broad swathes of northern and northwestern China, affecting Northwest China, southern parts of North China, and western and northern areas of the Huanghuai region. As temperatures soared, public discussion increased regarding whether an atmospheric phenomenon known as a "heat dome" was directly responsible for driving the persistent summer heatwave. In an interview published by People's Daily, a chief forecaster at China's National Meteorological Center clarified that "heat dome" is an illustrative popular science concept rather than a formally defined meteorological term. Forecasters use the phrase to describe a physical phenomenon where a large-scale, stable high-pressure atmospheric system remains stationary over a specific geographic area for an extended period. Like a giant pot lid covering the region, the high-pressure system prevents accumulated atmospheric heat from dispersing, resulting in continuous temperature rises near the ground. The expert clarified that the direct meteorological driver of the recent severe heat across Northwest and North China is actually a stable high-pressure ridge. Under the control of this high-pressure system, weather dynamics remain relatively stationary, producing largely cloudless skies. This allows strong solar radiation to continuously heat the Earth's surface. At the same time, air within the high-pressure system sinks toward the ground and compresses, causing temperatures to climb further in a process known as compressional heating. Because both horizontal and vertical heat dissipation are severely restricted, thermal energy progressively accumulates near the surface. In China during the summer season, the primary atmospheric drivers behind heat dome phenomena include the Subtropical High and mid-to-high latitude blocking highs. The Subtropical High primarily dictates heat patterns across the Jianghuai, Jiangnan, and South China regions, as well as the Sichuan Basin. In contrast, blocking highs occur more frequently in mid-to-high latitudes, characterized by stable positioning that causes sustained dry, clear, and hot weather over targeted regions. Both systems operate through identical warming mechanisms to generate heat dome effects. Addressing broader public concerns over increasingly frequent extreme weather, the forecaster emphasized that rising summer temperatures reflect the combined influence of synoptic weather systems and long-term climate change. In the short term, stagnant high-pressure systems generate local heating through compression and trapped radiation. In the long term, global climate change raises baseline temperatures, while local compounding factors such as severe soil drought and urban heat island effects further heighten human thermal discomfort during heatwaves.