Appearances in Hong Kong are important. This is a city where suits are still de rigueur for meetings and business functions, and many residents care about looking stylish. Slop around in flip-flops and baggy shorts and you will feel there's a neon "tourist" sign over your head. Pack your nicer pairs of jeans, slacks, or skirts, especially if you’re planning on going to a nice restaurant or out on the town.
From May through September conditions are seriously hot and sticky, but air-conditioning in hotels, restaurants, museums, and movie theaters can be arctic—keep a crushproof sweater or shawl in your bag. Don't forget your swimsuit and sunscreen; many large hotels have pools, and you may want to spend some time on one of Hong Kong's many beaches. In October, November, March, and April a jacket or sweater should suffice, but from December through February bring a light overcoat, preferably waterproof. Compact folding umbrellas can come in handy to protect against either rain or sun, but hotels will also lend you larger ones for the day.