Hong Kong Just Had Its Hottest Day Ever — Because of a Typhoon Nearby

Hong Kong recorded its hottest day in history on Sunday, August 9, 2026, as Typhoon Dolphin pushed warm air across the city before hitting China's coast hundreds of kilometers away.

The Hong Kong Observatory measured 36.9°C (about 98°F) at 5:50 p.m. local time. That beat the old record of 36.6°C set on August 22, 2017, right before Typhoon Hato arrived (The Guardian). The Observatory has been tracking temperatures since 1884 — 142 years. Its website confirmed the 36.9°C reading at the same time (HKO).

You might wonder why a typhoon made things hotter instead of cooler. Here is why: a typhoon is like a giant fan. Air rises fast at the center, but on the outer edges, air sinks back down. When air sinks, it gets squeezed and heats up — the same way air inside a bicycle pump feels warm when you compress it. As Dolphin moved north through the East China Sea, this sinking, heating air spread across southern China and over Hong Kong. Asharq Al-Awsat reported that this warm air was the direct cause of the record (Asharq Al-Awsat).

The Observatory issued a "very hot weather warning" on Sunday. That is part of a system the Observatory uses to warn people when heat could cause heatstroke or heat exhaustion. They told residents to drink water and avoid hard outdoor exercise.

In Sheung Shui, a town in northern Hong Kong near the border with Shenzhen, a weather station recorded 39.8°C (about 104°F). That is the highest reading anywhere in Hong Kong since the automatic weather station network began in the 1980s (The Guardian). The reason the Sheung Shui number is higher than the Observatory's 36.9°C is location: the Observatory sits near the city center, closer to the ocean, which keeps things slightly cooler. Inland areas heat up more.

Dolphin itself hit land near Yuhuan, in Zhejiang province, at about 5:30 p.m. local time (09:30 GMT) on Sunday. Its strongest winds reached 94 mph (151 km/h). That makes it the equivalent of a Category 1 hurricane on the scale used for Atlantic storms (The Guardian).

This combination — record heat in Hong Kong and a typhoon hitting land in Zhejiang — follows a pattern that happens often with western Pacific storms. When a typhoon passes north of Hong Kong, the city ends up in a spot where sinking air pushes temperatures up. The 2017 record happened the same way: Hato, a much stronger storm, was preceded by a heat spike as its sinking-air zone settled over Hong Kong.

What makes this event notable is the size of the new record. It beat the 2017 mark by 0.3°C, which is a meaningful jump for a 142-year series where the highest temperatures are all bunched close together. The Sheung Shui reading of 39.8°C, nearly 40°C, also signals that conditions were extreme even compared to past typhoon-related heat events.

The broader context here is the pattern forming in Hong Kong's temperature history. The city's hottest days have almost always been caused by nearby typhoons, not by regular heatwaves. That means this record tells us as much about Dolphin's path as it does about the overall climate. The two highest temperatures in 142 years both happened during approaching typhoons, nine years apart. That raises a question: is this heating effect getting stronger as ocean and air temperatures rise overall? One event alone cannot answer that. But it gives scientists another data point to study.

For Zhejiang, the focus now is on the storm itself: strong winds, coastal flooding, and heavy rain. At Category 1 strength, Dolphin can cause real damage, especially in coastal towns, though it is far less powerful than the worst storms to hit this part of China in recent years.