Best time to visit
Hong Kong's subtropical climate means the "best" time to visit depends heavily on your tolerance for heat and humidity versus your tolerance for slightly cooler, greyer days.
October to December — the sweet spot
Widely considered the most comfortable stretch: warm days, low humidity, clear skies, and it falls after the worst of typhoon season. Also the busiest period for exactly these reasons.
January to March — cool and dry, occasionally damp
Temperatures can drop enough to want a jacket, and a persistent damp mist ("plum rain" season's cousin) sometimes settles over the city in early spring, fogging up camera lenses and high-rise views alike.
April to September — hot, humid, and typhoon season
Summer brings serious heat and humidity, sudden downpours, and the annual typhoon season, which runs roughly May to November with peak risk in August and September. A typhoon signal 8 or above shuts down much of the city for the duration — rare, but worth knowing about if travelling in this window.