Summers are hot and humid in Hong Kong. The temperature starts increasing gradually from May. By late May to mid-September, temperature is often between 32°C-37°C. More discomfort is due to the humidity which rises to about 90%. Even the nights shows no sign of relief. Humidity level starts declining and weather conditions improve once September sets in. Also there is a lot of downpour during this season interrupted occasionally by mild cyclones and storms. However, the warning system of Hong Kong is very good. So, you need not to worry about the tropical storm.
    
The coldest months of the year are January and February when temperature lies between 5°C-10°C. The spring season is from March to May when the temperature is range between 16°C-27°C. The humidity level goes up to 84%. The fog and rain are quite frequent in this period of time. Late September to early December is the most pleasurable time of year when the temperatures is around 21°C-26°C and the humidity decreases nearly to 70%. The sky is clear and sunny during this time.

The months of October, November and December are the best to visit Hong Kong. There are lesser rains, no fears for the storms plus temperature and humidity is quite tolerable. Humidity and pollution levels comes down and the flowers blossom. The sight scenes are very beautiful and pleasing at this time of year.
 
The best tourist season in Hong Kong are the autumn and spring. But still tourists use to come to Hong Kong nearly all around the year, mainly the tourists from neighborhood country China. So, it is good that you get your flight and hotel reservations done in advance if you're planning a trip to Hong Kong. During the Chinese New Year or festive seasons, the travel season is at its peak in Hong Kong. Keep in mind that many package deals are offered by Hong Kong hotels which are very economical. There is a special discount during off season.

Hong Kong is a place where a tour can be planned at any time of the year provided that one has gathered complete information about the weather and all the safety precautions.