May weather forecast
Ha Long, Vietnam

May in Ha Long embraces the onset of tropical weather. Among the notable changes is an influx of substantial rainfall, with 163mm (6.42") recorded to fall over the course of May. Simultaneously, temperature highs, lows, and sea temperatures ascend, evaporating the increasing supply of rainwater. Despite the uptick in rainfall, the city's charm continues to captivate visitors, who are greeted by misty landscapes and sparkling rainforests. While the rainfall does dampen the sunlit hours, the city never loses its exotica.

Temperature

The average high-temperature in Ha Long during May registers at a still hot 33.3°C (91.9°F), maintaining a close resemblance to the previous month. Ha Long in May anticipates an average nighttime temperature of 24°C (75.2°F).

Heat index

May's heat index is appraised at a life-threatening hot 47°C (116.6°F). Remain alert: Heat exhaustion and heat cramps are predicted. Extended effort can lead to heatstroke.
In reference to the heat index, it's for places in shade and with a slight wind. If exposed to direct sunlight, the heat index could climb by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', is a metric representing the sensation of warmth when air temperature and moisture come together. The impact of weather on an individual can be subjective, affected by the person's activity and heat perception, which can vary due to elements including wind, clothing, and metabolic differences. Always consider that direct sunlight exposure might heighten the heat's effects, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold particular importance for children. Younglings frequently fail to recognize the requirement to rest and rehydrate. Thirst emerges late in dehydration - it is imperative to keep hydration levels high, particularly during extended physical exertions.
The body's innate mechanism to counteract overheating is through perspiration, as it leverages the cooling effects of sweat evaporation. An increase in relative humidity hinders the body's normal cooling function by reducing evaporation, thereby decreasing the rate of body cooling and enhancing the sense of warmth. Heat-related challenges, like dehydration, can be anticipated when body heat isn't managed effectively.

Humidity

The average relative humidity in May in Ha Long is 76%.

Rainfall

In May, the rain falls for 22.7 days. Throughout May, 163mm (6.42") of precipitation is accumulated. In Ha Long, during the entire year, the rain falls for 237.1 days and collects up to 1472mm (57.95") of precipitation.

Sea temperature

In Ha Long, in May, the average water temperature is 27.3°C (81.1°F).
Note: Ideal surface water temperatures for any water activity fall between 25°C (77°F) and 29°C (84.2°F), offering maximum enjoyment for lengthened periods.

Daylight

In May, the average length of the day in Ha Long is 13h and 8min.
On the first day of the month, sunrise is at 05:21 and sunset at 18:16. On the last day of May, in Ha Long, sunrise is at 05:10 and sunset at 18:29 +07.

Sunshine

In May, the average sunshine in Ha Long is 8.9h.

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 vulnerability from exposure to the Sun's UV rays for ordinary individuals.
Note: In May, the average maximum UV index of 7 translates into the following recommendations:
Adopt measures and apply sun safety strategies. Shielding from skin and eye damage is necessary. Avoid direct sunlight between the hours of 10 a.m. and 4 p.m., when UV radiation is at its peak. Keep in mind that shade structures may not provide complete protection. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes. Warning! The Sun's UV rays intensify with reflections from sand and water.