Record Heatwave Sweeps China as 40-Day Dog Days Begin

China officially entered its annual “sanfu” (dog days) period on July 15, 2026, with 20 provinces experiencing scorching temperatures that have already pushed the power grid in Chongqing to a record-breaking load of 30.67 million kilowatts. The National Meteorological Center has issued a yellow high-temperature warning as local areas in Xinjiang, Shaanxi, Sichuan, and Chongqing brace for temperatures exceeding 40°C, according to Xinhua News.

What Are China’s Dog Days?

Sanfu, known as China’s “dog days of summer,” is a traditional Chinese calendar concept that marks the hottest and most humid period of the year. The 2026 sanfu period will last 40 days — ending on August 23 — making it an “extended” version, 10 days longer than the previous year. This is determined by the traditional Chinese lunisolar calendar’s “geng day” calculation method, which dictates that the middle phase (zhongfu) lasts 20 days instead of the usual 10 in certain years.

According to traditional Chinese astrology, 2026 is a bingwu (Year of the Fire Horse), a so-called “dual-fire year” where both the Heavenly Stem and Earthly Branch are associated with the fire element. Folk tradition holds that such years bring particularly intense summer heat, as reported by People’s Daily.

Geographic Scope of the Heatwave

The National Meteorological Center’s yellow warning, issued at 6:00 a.m. on July 15, covers a vast swath of the country. Temperatures of 35–36°C are forecast across 20 provinces and regions, including Inner Mongolia (western), Xinjiang, Gansu (western), Shaanxi (southern), Hebei (central), Beijing (southern), Tianjin (southern), Henan (south-central), Anhui, Jiangsu (south-central), Shanghai, Hubei, Hunan (north-central), Jiangxi (north-central), Zhejiang, Fujian (northern), Sichuan (eastern), Chongqing, Guizhou (eastern), and Guangxi (western).

Localized areas are expected to face even more extreme conditions. The Turpan Basin in Xinjiang, southern Shaanxi, eastern Sichuan, and western Chongqing could see temperatures exceeding 40°C, while parts of Inner Mongolia, eastern Xinjiang, central Hebei, and several other provinces may reach 37–39°C.

Chongqing Power Grid Under Record Strain

The heatwave’s most immediate impact has been on electricity infrastructure. On July 14 at 5:11 p.m., Chongqing’s power grid load hit a historic 30.67 million kW, surpassing the previous record of 30.28 million kW by 390,000 kW, People’s Daily Chongqing reported. The surge was driven by widespread use of air conditioning and cooling equipment as temperatures soared.

Chongqing had issued its first high-temperature red alert of 2026 on July 14, covering 31 districts where temperatures were forecast to reach 40–42°C. This followed five consecutive days of orange alerts from July 6–10.

State Grid Chongqing Electric Power Company has mobilized extensive resources to manage the crisis. The utility has deployed over 4,700 personnel and 1,200 vehicles daily, conducted more than 6,000 equipment inspections ahead of the summer peak, and positioned 3 mobile substations and 29 medium-voltage power generation vehicles for emergency response. The company has also maintained 76 substations with on-site personnel and established 165 grid-monitoring stations.

A critical component of Chongqing’s power security is the Xinjiang-to-Chongqing ultra-high voltage transmission project, which can deliver up to 6 million kW — approximately one-fifth of the city’s peak demand. The city has also secured up to 11.87 million kW of external power purchases for 2026.

National Context and Broader Risks

The heatwave arrives against a backdrop of rising national electricity demand. The National Energy Administration had earlier projected that China’s summer peak electricity load could reach 1.6 billion kW in 2026, an increase of 90 million kW from 2025. The State Grid Corporation’s operating area alone was expected to exceed 1.3 billion kW, as reported by China Energy News.

Compounding the challenge, the National Meteorological Center has also forecast heavy rainfall over the next three days in parts of Northwest China, southern North China, Huanghuai, and South China, with flood risks in Guangdong, Guangxi, Shandong, Shaanxi, and Qinghai. This dual threat of extreme heat and flooding places additional strain on disaster response coordination.

Public Health Advisories

Meteorological authorities have urged local governments to strengthen measures against heat-related illnesses, drowning incidents, and wildfire risks in forests, tourist attractions, and urban areas. The public has been advised to minimize outdoor activities, and non-essential open-air work should be suspended during periods of extreme heat, according to ECNS.

Looking Ahead

With the 40-day sanfu period only just beginning, questions remain about whether additional record-breaking temperatures lie ahead and whether Chongqing’s power grid can sustain the load throughout the summer without resorting to rolling blackouts. The situation underscores the growing pressure on China’s energy infrastructure as climate change intensifies extreme weather events, and highlights the critical importance of long-distance transmission projects and demand-side management measures in ensuring energy security during peak summer months.

As the nation braces for what could be one of its hottest summers on record, all eyes will be on the interplay between traditional calendar predictions, modern infrastructure resilience, and the broader forces of a changing climate.