Do you need a coat in Hong Kong?

I'm curious, given the tropical climate of Hong Kong, is it really necessary to bring a coat when visiting the city? Wouldn't the year-round warm weather and humidity make such an item of clothing redundant? Or are there specific situations or locations where a coat might come in handy, perhaps in the evenings or indoors where air conditioning might be blasting? I'm genuinely interested in knowing if a coat is a practical addition to my packing list for a trip to Hong Kong.