April weather forecast
Hanoi, Vietnam

Summer reigns in April and Hanoi dresses up in high temperatures, making it one of the warmer months. Of note here, the maximum temperature recorded shoots up significantly to 30.8°C (87.4°F). This signals the commencement of the city's hot months. With an enhanced relative humidity, April witnesses a noticeable increased amount of rainfall that contributes to steamy-like weather conditions. This surge in temperature and humidity continues and intensifies into May, making way for a balmy summer.

Temperature

Observing a minor shift, the average high-temperature in Hanoi during April adjusts from March's warm 26.8°C (80.2°F) to a tropical 30.8°C (87.4°F). An average low-temperature of 21.8°C (71.2°F) is expected in Hanoi during April.

Heat index

The average heat index in April is estimated at a fiery hot 39°C (102.2°F). Exercise more precautions, heat cramps and heat exhaustion are potential risks. Continuous activity could precipitate heatstroke.
One should consider that heat index numbers are for shaded settings and light wind. Heat index values may be hiked up by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
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 shaped by additional aspects such as metabolic variations, physical activity, and clothing. It is noteworthy to mention that direct sunlight exposure can augment the felt temperature, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
The body's self-cooling mechanism is rooted in perspiration, where evaporating sweat cools down excessive warmth. Augmented relative humidity impedes typical body cooling mechanisms by lowering the evaporation rate, resulting in decreased body cooling and an amplified perception of heat. As the body accumulates more heat than it can release, body temperature goes up, increasing the risk of heat-related health issues.

Humidity

In Hanoi, Vietnam, the average relative humidity in April is 77%.

Rainfall

In Hanoi, in April, during 14.8 rainfall days, 32mm (1.26") of precipitation is typically accumulated. Throughout the year, there are 181.2 rainfall days, and 595mm (23.43") of precipitation is accumulated.

Daylight

The average length of the day in April is 12h and 38min.
On the first day of April in Hanoi, sunrise is at 05:49 and sunset at 18:11. On the last day of the month, sunrise is at 05:26 and sunset at 18:21 +07.

Sunshine

In Hanoi, the average sunshine in April is 7.2h.

UV index

In Hanoi, the average daily maximum UV index in April is 6. A UV Index of 6 to 7 symbolizes a high threat to health from unsafe exposure to UV radiation for the average person.
Note: A maximum high UV index of 6 in April translates into the following recommendations:
Undertake precautions and comply with sun safety standards. Protection from skin and eye injury is vital. Attempt to stay under shade and limit exposure to the Sun between 10 a.m. and 4 p.m., when UV radiation is at its peak. Remember, devices such as parasols or canopies might not provide complete sun protection. A hat with a broad brim is indispensable, filtering out up to half of UV rays.