Hong Kong is a transient city I've moved to 3 times in the last decade. Originally a wandering expat, I grew to knew the neighborhoods like the back of my hand. Having language proficiency helped, but Hong Kong is also one of the most foreign friendly cities out there.
Best Time To Visit Hong Kong
Hong Kong has a tropical climate, with average temperatures ranging from 16 °C (60.8 °F) in January and February to 28 °C (82.4 °F) in July and August. The island has beautiful but hot summers. Some of the clearest, least polluted days come during the heat, but both temperatures and humidity are high. If you can withstand the temperatures, blue skies abound during the summer.
During the winter temperatures typically don't drop below 10 degrees Celsius, or in the low 50s Fahrenheit. For cooler temperatures winter months are a nice time to travel, particularly November and December.
Hong Kong Highlight Itinerary
If I were visiting 24 hours for the first time, here's what I'd do:
1)Victoria Peak-For the active ones, there are both steep/short and long/winding hikes to the top. The shorter hike starts at the end of Old Peak Road (take a cab to the end of old peak road and you won't miss it) and is a steep but tree lined shady hike to the top. For the average fit person it should take about 20 minutes, but be forewarned, the hill will certainly get your blood pumping. Otherwise get to the peak tram in Central and take a leisurely uphill tram to see the view. It's not necessary to goto the skydeck, the free views are pretty similar. The views have some parallels with the views in Nagasaki, which are also stunning.
2)Dimsum-There's nothing dim about dimsum- the wheeled carts of food feature brightly decorated delicacies made for sharing. It's Chinese tapas. I typically take visitors to the Maxim's on the top floor of city hall (with a view to boot)-don't forget the baked savory pineapple pork buns and indulge on that fresh mango dessert at the end.
3) Tram (Ding ding)-The easiest and cheapest transport in HK is the 2 dollar tram. Well it might be 2.50 HKD by now, but not much more. Go on the top deck for open air views and you can ride from the west side of HK island to the east. (or vice versa) The tram line traverses major roads and is one of the best ways to experience the island. Apparently also easy to catch Pokemon.
4)Star Ferry-A ferry between HK Island and the Kowloon peninsula (which is the closest to China). Also a cheap transport, hop on at Central (HK) or TST (Kowloon) pier for a short ride and plenty of photo ops.
5) Temple street night market-Beginning early evening (by 5pm) vendors turn a couple of streets in Mongkok into open air markets. (Get out at Mongkok mtr and look for signs) These are extremely diversified markets selling clothes, wallets, purses, (“LV”, “Gucci”, “Prada”, etc) knick knacks, toys, and all sorts of bits and bobs. Even if you're not a shopper it's an experience you want before shopping goes the way of the world wide web and drones. Do bargain.
Bonus round: Goto Lan kwai fong for a nightlife district on steroids.