Hong Kong
Hong Kong
Long-term weather forecast
Long-term weather forecast

September weather forecast and Climate
Hong Kong, Hong Kong

A bird
A bird's eye view of the lit city of Hong Kong, in the Hong Kong Island
September is a transitional month with the summer heat still around and the autumn not yet in full bloom. Rain tapers down to 12" (304.8mm) with a drop in humidity as the sun returns on the horizon for a daily 6 hours.
Temperatures are usually around 80°F (26.7°C) with the average temperature range in a hot 78°F (25.6°C) to 86°F (30°C) as the heat is on a gradual reduction path. An occasional cyclone is still on the calendar with wind-induced low-pressure areas over the South China Sea.
Sunny days are back again as the cloud cover dwindles and the Mid-Autumn Festival in late September celebrates the arrival of the pleasant weather. For fishing lovers, Lamma Island Hiking Tour with its 6000 years of fishing history is a great place to explore with the reduced rain intensity. Light clothes are the order of the day while an umbrella is still a handy accessory to shield the rain!
  • The average high temperature in September: 30.1°C

The warmest month (with the highest average high temperature) is July (31.4°C).
The month with the lowest average high temperature is January (18.6°C).

  • The average low temperature in September: 25.8°C

The month with the highest average low temperature is July (26.8°C).
The coldest month (with the lowest average low temperature) is January (14.5°C).

  • The average humidity in September: 78%

Months with the highest relative humidity are April and May (83%).
The month with the lowest relative humidity is December (69%).

  • The average rainfall in September: 327.6mm

The wettest month (with the highest rainfall) is June (456.1mm).
The driest month (with the lowest rainfall) is January (24.7mm).

  • The average rainfall days in September: 14.7 days

The month with the highest number of rainy days is June (19.1 days).
The month with the lowest number of rainy days is December (4.5 days).

  • The average sea temperature in September: 28.3°C

The best month for swimming (with the highest average sea temperature) is July (29.1°C).
The coldest month (with the lowest average sea temperature) is February (18.9°C).

  • The average daylight in September: 12h

Months with the longest days are April, May, June, July and August (Average daylight: 13h).
Months with shortest days are January, February, November and December (Average daylight: 11h).

  • The average sunshine in September: 5.7h

The month with most sunshine is July (Average sunshine: 6.8h).
The month with least sunshine is March (Average sunshine: 2.9h).

  • The average UV index in September: 11

Months with the highest UV index are April, May, June, July and August (UV index 12).
Months with the lowest UV index are January, November and December (UV index 7).