September weather forecast
Happy Valley, Hong Kong

During September, Happy Valley begins to bid farewell to summer with a gradual reduction in temperature. The drop offers a slight comfort from the high humidity levels experienced over the past few months. The city continues to enjoy long hours of sunshine, favourable for outdoor activities. October promises a greater relief with a further decrease in rainfall and temperature. Notably, September experiences a marginal drop in average wind speed to 13.5km/h (8.4mph), contributing to the easing weather conditions.

Temperature

As Happy Valley welcomes September, the average high-temperature is noted at a moderately hot 29.6°C (85.3°F), closely aligning with the preceding month. Happy Valley experiences a minimal drop from daytime high temperatures, recording an average low-temperature of 26.5°C (79.7°F) throughout September.

Heat index

For September, the heat index is appraised at a fiery hot 36°C (96.8°F). Ensure heightened precautions, risk of heat cramps and heat exhaustion is significant. Sustained activity could provoke heatstroke.
In reference to the heat index, it's for places in shade and with a slight wind. Heat index values have the potential to be boosted by 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'apparent temperature' or 'real feel', is an indicator that blends the effects of temperature and humidity to depict perceived warmth. The individual's impression of temperature can be affected by numerous factors such as metabolic variations, physical exertion, and attire. Taking into account that direct sunlight can boost the heat effect, the heat index may rise by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Children often fail to understand the importance of rest and rehydration. Thirst is a late manifestation of dehydration - hence, it is crucial to stay hydrated, especially during ongoing physical activities.
To prevent overheating and help regulate its internal temperature, the human body sweat and rely on the evaporation to cool down. Under conditions of high temperature and humidity (enhanced heat index), sweat production is compromised, exacerbating the sensation of warmth. If heat absorption isn't effectively countered by the body's cooling methods, body temperature surges, hinting at potential problems.

Humidity

In Happy Valley, the average relative humidity in September is 77%.

Rainfall

In Happy Valley, in September, during 22.7 rainfall days, 155mm (6.1") of precipitation is typically accumulated. In Happy Valley, during the entire year, the rain falls for 224.5 days and collects up to 1264mm (49.76") of precipitation.

Daylight

In Happy Valley, 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 18:40. On the last day of September, sunrise is at 06:14 and sunset at 18:11 HKT.

Sunshine

In Happy Valley, the average sunshine in September is 8.4h.

UV index

May through September, with an average maximum UV index of 7, are months with the highest UV index. A UV Index reading of 6 to 7 represents a high threat to health from unsafe exposure to UV radiation for ordinary individuals.
Note: The maximum daily UV index of 7 during September translates into the following directions:
Shield from overexposure. Defense against sun-related harm is required. Between 10 a.m. and 4 p.m., the Sun emits the most powerful UV radiation. Limit direct exposure to the Sun during these hours. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.