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

As Hanoi transitions into April, the average high-temperature is observed to slightly rise from a moderately hot 26.8°C (80.2°F) in March to a tropical 30.8°C (87.4°F). During the nights in April, Hanoi observes an average low-temperature of 21.8°C (71.2°F).

Heat index

The heat index in April is evaluated at a torrid 39°C (102.2°F). More safety actions are required, heat exhaustion and heat cramps are probable. Long-term activity may precipitate heatstroke.
Data suggests that the heat index is set for environments in shade and with a light wind. A rise in the heat index by 15 Fahrenheit (8 Celsius) degrees may result from direct sunlight exposure.
Note: The heat index, also known as 'felt air temperature' or 'real feel', quantifies the warmth felt when relative humidity is considered. The influence of weather is personal, with a diverse population experiencing it differently due to differences in body mass, stature, and degree of activity. Given the impact of direct sunlight, it's noteworthy that the felt temperature can rise by 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for 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, followed by sweat evaporation, is the human body's chief method to maintain a balanced temperature. In the presence of high relative humidity, the evaporation rate diminishes, resulting in the body retaining more warmth compared to dry conditions. Should the body fail to balance its heat gain, the escalating temperature poses health challenges.

Humidity

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

Rainfall

In Hanoi, Vietnam, during April, the rain falls for 14.8 days and regularly aggregates up to 32mm (1.26") of precipitation. In Hanoi, during the entire year, the rain falls for 181.2 days and collects up to 595mm (23.43") of precipitation.

Daylight

The average length of the day in April is 12h and 38min.
On the first day of April, 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

The average daily maximum UV index in April is 6. A UV Index of 6 to 7 symbolizes a high health risk from unsafe exposure to UV radiation for the average person.
Note: A maximum UV index of 6 in April translates into the following recommendations:
Take precautions against overexposure. Protection against sun damage is needed. The Sun's UV radiation is most potent between the hours of 10 a.m. and 4 p.m. Try to avoid direct sunlight during this time. Always opt for UVA and UVB-resistant sunglasses on radiant days.