September weather forecast
Sai Wan, Hong Kong

September starts to slowly wind down from the peak of summer in Sai Wan. The city sees a fusion of late summer heat and the early arrival of autumnal cool breezes. Despite the first rustle of fallen leaves, afternoons remain sweltering, and the city's general atmosphere carries a residual humidity. The decline in rainfall is worth noting, decreasing significantly to a still substantial 155mm (6.1"). The dramatic shifts in Sai Wan's weather add a unique layer to its appeal.

Temperature

September's climate shows a minor adjustment in average high-temperatures to a moderately hot 29.6°C (85.3°F) from August's 30.5°C (86.9°F). Sai Wan's nocturnal readings in September exhibit minimal variation from the daytime temperatures, averaging at a still warm 26.5°C (79.7°F).

Heat index

In September, the average heat index is appraised at a fiery hot 36°C (96.8°F). Emphasize additional safety, risk of heat cramps and heat exhaustion is high. Continuous activity might result in heatstroke.
Heat index evaluations are typically in the context of light winds and shaded environments. Under direct sunshine, the heat index values might be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', combines both the air temperature and the humidity level to give a perceived human temperature. Additional factors encompassing metabolic differences, the level of physical activity, and clothing can impact the individual's perception of temperature. With direct sunlight, be aware that it might enhance the heat sensation, raising the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Children frequently do not comprehend the need for rest and hydration. Thirst is an advanced stage of dehydration - staying hydrated, especially during extended physical exercises, is essential.
To combat high temperatures, the human body perspires and relies on sweat evaporation for cooling. When the air contains significant moisture, the efficiency of the evaporation process decreases, preventing the body from cooling down effectively and creating a feeling of overheating. Excessive heat gain, when not shed effectively by the body, can result in increasing body temperatures and related hazards.

Humidity

In September, the average relative humidity is 77%.

Rainfall

In Sai Wan, during September, the rain falls for 22.7 days and regularly aggregates up to 155mm (6.1") of precipitation. In Sai Wan, during the entire year, the rain falls for 224.5 days and collects up to 1264mm (49.76") of precipitation.

Daylight

The average length of the day in September in Sai Wan is 12h and 17min.
On the first day of September in Sai Wan, sunrise is at 06:06 and sunset at 18:40. On the last day of the month, sunrise is at 06:14 and sunset at 18:12 HKT.

Sunshine

In Sai Wan, the average sunshine in September is 8.4h.

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 health hazard from exposure to the Sun's UV radiation for the average person.
Note: The maximum daily UV index of 7 in September interprets into the following recommendations:
Continue precautions and advocate sun safety advice. Deterrence of sunburn is indispensable. Avoid direct Sun exposure and stay in the shade between 10 a.m. and 4 p.m., a time when UV radiation is most intense, noting that not all shade structures offer full protection. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.