April weather forecast
Ha Long, Vietnam

April’s weather in Ha Long marks the shift towards steadily warming days. A significant amount of rainfall has been recorded at 53mm (2.09") in April, indicating the progression into the rainy season. The region's natural beauty flourishes, captivating visitors with its verdant landscapes. Sea temperatures elevate, maintaining a pleasant balance with the rising onshore temperatures. As the precipitation increases, so does the vibrant ecosystem of this Vietnamese city.

Temperature

Ha Long's weather in April shows a minor rise in the average high-temperature, moving slightly up from March's warm 26.8°C (80.2°F) to a hot 30.6°C (87.1°F). Throughout April, an average low-temperature of 21.4°C (70.5°F) is experienced.

Heat index

The average heat index in April is estimated at a sweltering 38°C (100.4°F). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
Given the heat index, its values are aligned with shaded sites and gentle winds. Direct exposure to sunshine could lead to a heat index increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', arises from combining readings of air temperature and relative moisture content. A person's impression of weather can be shaped by several aspects, among them metabolic variations, pregnancy, and levels of physical activity. One's exposure to direct sunlight has the potential to intensify the heat sensation, increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Kids are usually more vulnerable than adults, given their lesser sweating ability. Along with their larger skin surface relative to their small stature and the excess heat due to their activity, their risk is amplified.
Perspiration, which is the evaporation of sweat, is a primary way the human body manages and dispels excessive warmth. When air moisture content is high, the cooling process through evaporation is not as efficient, leading to an ineffective body cooling process and a feeling of overheating. Potential thermal conditions emerge as the body's heat gain outpaces its cooling mechanisms.

Humidity

In Ha Long, Vietnam, the average relative humidity in April is 76%.

Rainfall

In Ha Long, in April, during 20.3 rainfall days, 53mm (2.09") of precipitation is typically accumulated. Throughout the year, in Ha Long, there are 237.1 rainfall days, and 1472mm (57.95") of precipitation is accumulated.

Sea temperature

In Ha Long, the average seawater temperature in April is 22.4°C (72.3°F).
Note: For individuals prone to feeling cold, swimming in 23°C (73.4°F) is still regarded as intolerable. A wetsuit is not a necessity, but sunshine, wind, and air temperature are essential factors for relishing swimming at 22.4°C (72.3°F).

Daylight

The average length of the day in April is 12h and 38min.
On the first day of April, sunrise is at 05:44 and sunset at 18:06. On the last day of the month, sunrise is at 05:21 and sunset at 18:16 +07.

Sunshine

The average sunshine in April is 7.8h.

UV index

The months with the highest UV index are April through August, with an average maximum UV index of 7. A UV Index estimate of 6 to 7 represents a high health risk from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: The UV index of 7 during April leads to these advisories:
Use measures and accept sun safety conventions. Guarding against skin and eye trauma is of high priority. Avoid exposure to the Sun and try to stay in the shade between 10 a.m. and 4 p.m., when UV radiation is most potent, but be aware that parasols or canopies may not offer full protection. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat. Be careful! The Sun's UV radiation is accentuated by reflecting off sand and water.