September weather forecast
Kam Shan, Hong Kong

The first month of the autumn, September, is also a hot month in Kam Shan, Hong Kong, with an average temperature fluctuating between 30°C (86°F) and 26.3°C (79.3°F).

Temperature

Kam Shan's weather in September, with an average high-temperature of a still hot 30°C (86°F), subtly shifts from August's 31.3°C (88.3°F). A mild drop to an average of 26.3°C (79.3°F) marks the nights during September.

Heat index

Throughout September, the heat index is estimated at a torrid 37°C (98.6°F). Heightened safety actions are necessary, heat cramps and heat exhaustion are probable. Persistent activity may lead to heatstroke.
Heat index values are typically calculated for conditions of shade and a light breeze. The heat index may scale up by 15 Fahrenheit (8 Celsius) degrees with direct sun exposure.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', ties air temperature with relative humidity to produce the perceived temperature sensation. The effect is personal, with varied weather perceptions among individuals due to differences in body mass, stature, and physical activity. It is essential to realize that direct sunlight can escalate the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. In general, younger individuals are at greater risk than adults because they tend to sweat less. Also, having a larger skin surface to body size ratio and greater heat production due to their active behavior contribute to this danger.
The human body normally cools itself by perspiration. Excessive warmth is eliminated from the body by evaporation of sweat. Relative humidity in excess curtails evaporation, therefore reducing heat dissipation from the body, leading to feelings of excess heat. Overheating and potential dehydration arise when body heat gain eclipses its release capability.

Humidity

In Kam Shan, the average relative humidity in September is 76%.

Rainfall

In Kam Shan, during September, the rain falls for 19.8 days and regularly aggregates up to 94mm (3.7") of precipitation. In Kam Shan, during the entire year, the rain falls for 187.1 days and collects up to 771mm (30.35") of precipitation.

Daylight

In September, the average length of the day is 12h and 17min.
On the first day of September, 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

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 health vulnerability from unsafe exposure to UV radiation for ordinary individuals.
Note: In September, the average maximum UV index of 7 translates into the following recommendations:
Shield from overexposure. Defense against sun-related harm is required. Stay in the shade and limit direct sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its strongest. Remember, however, that not all shade structures provide full sun protection. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.