September weather forecast
Tin Shui Wai, Hong Kong

Following August, September heralds gradual changes with reducing daily rainfall totals, daylight, and temperatures. Despite marking the tail-end of the rainy season, the city experiences notable rainfall, approximately 150mm (5.91"). The temperatures vary from a high of 30°C (86°F) to a low of 26.4°C (79.5°F). Inevitably, cooling breezes and shorter days signal the impending end of the long, wet summer. Subsequently, the extended daylight period and increased sunshine hours lend a balanced transition from wet to drier weather.

Temperature

The arrival of September in Tin Shui Wai sees an average high-temperature of a still hot 30°C (86°F), hardly diverging from August's 31.3°C (88.3°F). September nights in Tin Shui Wai, Hong Kong, register a minor temperature decline, steadying at a warm 26.4°C (79.5°F).

Heat index

For most parts of September, the heat index is evaluated at a torrid 37°C (98.6°F). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
It is emphasized that the heat index's values are meant for shaded zones with mild winds. The presence of direct sunlight can raise the heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is found by incorporating humidity levels into the air temperature measurement. Depending on the activity and the individual's heat perception, which may vary due to factors including wind, clothing, and metabolic variations, this effect remains subjective. Being aware that direct sunlight can impact the felt heat might mean an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Kids frequently fail to realize the necessity for resting and hydrating. Thirst is an advanced indication of dehydration - hence, maintaining hydration, especially during extended physical activities, becomes essential.
When it comes to cooling down, the human body's primary method is through perspiration, making use of sweat evaporation to eliminate excess heat. In the presence of high relative humidity, the evaporation rate diminishes, resulting in the body retaining more warmth compared to dry conditions. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.

Humidity

In September, the average relative humidity is 76%.

Rainfall

In September, in Tin Shui Wai, the rain falls for 22.7 days. Throughout September, 150mm (5.91") of precipitation is accumulated. In Tin Shui Wai, during the entire year, the rain falls for 207.6 days and collects up to 1194mm (47.01") of precipitation.

Daylight

The average length of the day in September is 12h and 17min.
On the first day of the month, sunrise is at 06:06 and sunset at 18:41. On the last day of September, in Tin Shui Wai, sunrise is at 06:15 and sunset at 18:12 HKT.

Sunshine

The average sunshine in September is 8.2h.

UV index

The months with the highest UV index are May through September, with an average maximum UV index of 7. A UV Index value of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV radiation for the average person.
Note: During September, 7 as the daily maximum UV index converts into the following advice:
Resist overexposure. Safeguarding from solar damage is indispensable. Minimize exposure to direct sunlight and seek shade from 10 a.m. to 4 p.m., when UV radiation is most intense, but remember that shade structures may not offer complete protection. During bright days, sunglasses that offer UVA and UVB defense are recommended.