April signifies the onset of a significantly warmer phase in
Hong Kong’s annual weather cycle. Alongside the noticeable warmth, the levels of precipitation experience a steep surge taking a jump from 82mm (3.23") in
March to a substantial 175mm (6.89"). Such a shift alters the city’s atmosphere, with more instances of overcast skies and a higher incidence of wet weather days. While daytime warmth persists, evenings are liable to be accentuated with sporadic rain showers. In general, April is the threshold month between the mild conditions of the early year and the heat and humidity of the summer months.
Temperature
The start of April in Hong Kong, Hong Kong, brings a subtle rise in the average high-temperature, moving from an agreeable 21.4°C (70.5°F) in March to a moderately hot 25°C (77°F). Hong Kong maintains a near steady average temperature of 20.8°C (69.4°F) during the nights of April, demonstrating little drop from daytime highs.
Humidity
The months with the highest humidity are April and
May, with an average relative humidity of 83%.
Rainfall
In April, in Hong Kong, the rain falls for 12 days. Throughout April, 175mm (6.89") of precipitation is accumulated. Throughout the year, in Hong Kong, Hong Kong, there are 137.8 rainfall days, and 2398mm (94.41") of precipitation is accumulated.
Sea temperature
In April, the average sea temperature in Hong Kong is 22.8°C (73°F).
Note: If someone is sensitive to cold, the enjoyment of swimming in 22.8°C (73°F) water hinges on factors like sunshine, wind, and the current air temperature. (For context: Olympic swimming competitions are held in water temperatures of 25°C (77°F) to 28°C (82.4°F).)
Daylight
The average length of the day in April is 12h and 40min.
On the first day of April in Hong Kong, sunrise is at 06:15 and sunset at 18:38. On the last day of the month, sunrise is at 05:51 and sunset at 18:49 HKT.
Sunshine
In April, the average sunshine is 3.4h.
UV index
The months with the highest UV index are April through
August, with an average maximum UV index of 12. A UV Index reading of 11, and higher, represents an extreme health hazard from exposure to the Sun's UV rays for ordinary individuals.
Note: A maximum daily UV index of 12 during April morphs into the following directions:
Enforce every vital precaution. Those with light skin could endure burns in a matter of minutes. Stay in the shade and avoid direct Sun exposure from 10 a.m. to 4 p.m., a time when UV radiation is at its strongest, and remember that parasols or canopies do not offer full protection. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. Limiting time under the Sun is advisable, especially for individuals who tend to burn. Ensure using sunscreen with a 30 SPF or higher. Heads up! The reflection of sand and water notably intensifies UV rays from the Sun.