Hong Kong weather is warm as the region features a sub-tropical climate and although conditions can be hot and humid, particularly during summer, winter temperatures do drop a little thanks to sea breezes which cool the region. Summer occurs between June and September and is characterised by hot, humid and long days where temperatures often reach or exceed 32°C. Nightfall also offers little respite from the heat with temperatures only dropping marginally to a minimum of 25°C.
Summer is also typhoon season, the only real natural disasters that Hong Kong is prone to. Although considered natural disasters, these typhoons will not endanger the safety of tourists very much. A warning system is in place in Hong Kong and as long as visitors heed all of these warnings they shouldn't encounter a problem. The only real impact typhoons have on Hong Kong is the ceasing of non-essential activities such as local business and retail, who close until the storm has passed.
Autumn occurs from late September early November to December and is generally considered the most comfortable time to visit Hong Kong as temperatures drop to between 21°C and 24°C with less humidity than Spring and far less humidity than Summer. Spring occurs from March to May and although average temperatures also sit around 21°C and 24°C, this is also the 'wet' season, making for rainy and more humid conditions.
Winter is quite mild, particularly during the day when temperatures sit around a comfortable 18°C to 22°C however drop significantly at night, sitting at 10°C or even the high single digits, particularly further outside the city. Generally Hong Kong winters begin dry and mild but tend towards cooler and wetter weather as the season progresses, however cold weather is brief. Although most buildings and homes are air conditioned to cope with the summer heat, these are rarely required for heating in winter. As temperatures generally don't drop too low, locals usually just wear a few more layers to protect themselves on cooler days and nights.