Hottest day of the year ushers in 9 days of rain, as Hong Kong logs over 6,000 instances of lightning on Friday

Hongkongers sweated through the hottest day of the year on Friday, with the Observatory (HKO) recording a maximum temperature of 34.6 degrees Celsius at its headquarters. Yung Shue Wan, Lamma Island on Friday, June 5, 2026. Photo: HKFP. The mercury neared 37 degrees Celsius in the northern part of the territory. Maximum temperatures in Hong Kong on June 5, 2026. Photo: HKO. Meanwhile, the Observatory noted 1,263 instances of cloud-to-ground lightning on Friday, and 4,859 cases of cloud-to-cloud lightning. The city is now set to see nine days of rain, the weather service predicts. See also: How Hong Kong’s elderly face deadly heat inside cramped cage homes Cloud-to-ground lightning count distribution on June 6, 2026. Photo: HKO. “A broad trough of low pressure will linger over the vicinity of the coast of southern China to the northern part of the South China Sea during the weekend to midweek next week,” the Observatory said. The amber rainstorm warning was raised at 10am on Saturday as violent gusts swept into the territory, raising the risk of flooding. See also: NGO warns hot weather can worsen air quality, urges gov’t action on pollutants and cooling measures in hot districts Climate crisis Friday marked the hottest “Grain in Ear” solar term ever documented. The ninth traditional solar term, known in Chinese as Mangzhong, signifies a period when awny crops like wheat are ready to harvest. This week, environmental NGO Friends of the Earth urged the Hong Kong government to prioritise the climate crisis and strengthen its climate adaptation policies, with the city expected to endure an extremely hot summer. A heatwave in Hong Kong in late May 2026. Photo: Kyle Lam/HKFP. The Intergovernmental Panel on Climate Change has warned that the intensity and frequency of heatwaves have continued to increase since the 1950s due to human-caused climate change. The prevalence of greenhouse gases like carbon dioxide – which trap heat in the atmosphere – raises the planet’s surface temperature, with hotter, longer heatwaves putting lives at risk. See also: How extreme heat became the deadliest silent killer among world weather disasters Hong Kong has already warmed by 1.7 degrees Celsius since the Industrial Revolution, research NGO Berkeley Earth says . Heat and humidity may reach lethal levels for protracted periods by the end of the century, according to a 2023 study , making it impossible to stay outdoors in some parts of the world.