May weather forecast
Happy Valley, Hong Kong

May in Happy Valley shows a clear sign of the hot weather setting in, with temperatures soaring both during the day and night. The sky paints a beautiful picture, with the near-perfect visibility of 9 kilometers. The setting sun gives gravity to the city's radiant appeal. In the advance towards June, the rainfall amount peaks. Importantly, in May, there's a significant growth in relative humidity, reaching a high of 84%.

Temperature

May brings a slight elevation in the average high-temperature, transitioning from April's warm 24.5°C (76.1°F) to a still moderately hot 27.7°C (81.9°F). Happy Valley consistently logs a low temperature averaging a still moderately hot 24.9°C (76.8°F) during May, a modest drop from daytime temperatures.

Heat index

The average heat index in May is computed to be a hot 32°C (89.6°F). Long-standing exposure coupled with ongoing activity could result in exhaustion, possibly causing heat cramps.
For clarity, heat index numbers account for light winds and areas under shade. With exposure to direct sunshine, the heat index could climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', provides an understanding of perceived warmth by combining temperature and relative humidity. Factors such as metabolic variation, pregnancy, and physical activity play a role in one's impression of weather. In direct sunlight, the heat's impact can be heightened, potentially leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Young ones are generally more prone to risk than adults due to their reduced ability to sweat. Their large skin surface area relative to their diminutive bodies and elevated heat production from their activities further enhance this risk.

Humidity

With an average relative humidity of 84%, May is the most humid month.

Rainfall

In Happy Valley, in May, during 22.9 rainfall days, 171mm (6.73") 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

The average length of the day in May is 13h and 13min.
On the first day of May, sunrise is at 05:50 and sunset at 18:49. On the last day of the month, sunrise is at 05:38 and sunset at 19:03 HKT.

Sunshine

In May, the average sunshine 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 reading of 6 to 7 represents a high health hazard from exposure to the Sun's UV rays for the ordinary person.
Note: The daily maximum UV index of 7 in May interprets into the following advice:
Take precautions against overexposure. Fair-skinned people may get burned in less than 20 minutes. The hours from 10 a.m. to 4 p.m. have the most intense UV radiation. As much as possible, limit direct sun exposure during this period. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.