Hong Kong's October Heat Linked to El Nino; Warmer Winter Likely, Expert Says

Hong Kong’s exceptionally warm October weather is being driven by a combination of a super typhoon, El Nino and global warming, according to climate expert Amos Tai. He has warned that temperatures above the usual level are likely to continue through the winter.

The warning comes after autumn temperatures across the city rose above 30 degrees Celsius (86 Fahrenheit) during the past few weeks. The unusually high readings have made October exceptionally warm and have raised the possibility that Hong Kong could also experience a warmer-than-usual winter.

Professor Amos Tai Pui-kuen, of the earth and environmental sciences department at the Chinese University of Hong Kong, explained the weather pattern on Wednesday. He said the current heat was linked to three factors working together: a super typhoon, El Nino and global warming.

According to Tai, El Nino has changed the paths that typhoons normally take. It has also weakened the northeasterly winds that usually reach Hong Kong during autumn. Those winds are part of the seasonal weather pattern in the city, but their reduced strength has contributed to the unusually warm conditions.

Tai explained that the effect of El Nino is particularly important when the phenomenon becomes especially strong. “A ‘super’ El Nino means that courses of typhoons would move more northerly … if and when typhoons do hit Hong Kong, because of the high sea level temperatures, there will be more heat and steam evaporating, which contributes to a stronger typhoon, too,” he said.

His explanation links the movement and strength of typhoons with the wider weather conditions around Hong Kong. The altered typhoon paths are one part of the pattern, while the weaker northeasterly winds are another. At the same time, higher sea level temperatures provide more heat and allow more steam to evaporate, according to Tai.

The combination of these factors helps explain why temperatures have remained unusually high through October instead of following the cooler pattern normally associated with the season. The city has recorded temperatures above 30 degrees Celsius (86 Fahrenheit) over the past few weeks, as autumn conditions have continued to bring exceptional warmth.

Tai’s warning also extends beyond October. He said above-normal temperatures are likely to persist through the winter, meaning the warmer conditions may not end with the autumn season. The assessment points to the possibility of a winter in Hong Kong that is warmer than usual.

The outlook is based on the interaction of the super typhoon, El Nino and global warming described by the climate expert. Tai’s comments do not present the October heat as the result of a single factor. Instead, they explain it as the outcome of several conditions affecting typhoon behaviour, wind strength and heat in the surrounding sea.

For Hong Kong, the immediate concern is that the unusually warm weather has continued during a period when temperatures would normally be expected to ease. With temperatures already above 30 degrees Celsius (86 Fahrenheit) across the city in recent weeks, the possibility of continued warmth has become a key part of the weather outlook.

The report was published by South China Morning Post.