Hong Kong summer humidity isn't just hot, it's a special kind of miserable that soaks through clothes within minutes of stepping outside air conditioning. June through September averages 35°C with 85-95% humidity — Basically like breathing through a wet towel while wearing plastic bags.

Your shirt will be drenched walking slowly from Central MTR to IFC Mall (200 meters). Forget looking decent in photos. Plan your entire itinerary around air-conditioned refuges: malls like Pacific Place, MTR stations, and restaurants become survival stops every 15-20 minutes. Pack 2-3 shirts per day and accept that you'll look like you just finished a workout.

October through April is infinitely better for actually enjoying Hong Kong's outdoor attractions like Dragon's Back hike or Star Ferry rides. Summer visitors basically live underground in MTR passages and shopping centers. If you must visit June-September, embrace the indoor culture and enjoy some of the world's best mall food courts.