April weather forecast
Vientiane, Laos

April brings about the highest average temperatures in Vientiane between 23.8°C (74.8°F) to 34.3°C (93.7°F) along with an increase in rainfall from 34mm (1.34") in March to 85mm (3.35"). It heralds the arrival of the monsoon season, paving the way for an uptick in humidity in the coming months. Despite the heat and rainfall, the region retains its vibrant tropical allure, offering a unique experience to its travelers. The early sunsets coupled with significant rainfall make April a good time for indoor activities.

Temperature

The warmest time of the year is April, with temperatures averaging a high of 34.3°C (93.7°F) and a low of 23.8°C (74.8°F).

Heat index

In April, the average heat index is estimated at a life-threatening hot 47°C (116.6°F). Keep on guard: Heat exhaustion and heat cramps are probable. Heatstroke is a possible danger with ongoing physical activity.
Metrics for the heat index primarily focus on shaded spots and light wind conditions. The presence of direct sunlight can raise the heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'real feel', quantifies the warmth felt when relative humidity is considered. Elements such as metabolic variations, pregnancy, and physical exertion can influence one's weather perception. Taking into account that direct sunlight can boost the heat effect, the heat index may rise by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young ones often ignore the need to take a break and drink fluids. Thirst is a late-stage symptom of dehydration - hence, maintaining hydration, particularly during extended physical activities, is crucial.
To achieve cooling, the human body employs perspiration, relying on the subsequent evaporation of sweat. In circumstances of high air temperature and humidity (high heat index), the body's perspiration is restricted, heightening the feeling of warmth. When heat uptake goes beyond the body's cooling mechanisms, there's a surge in body temperature, posing health risks.

Humidity

In Vientiane, Laos, the average relative humidity in April is 69%.

Rainfall

In April, the rain falls for 8 days. Throughout April, 85mm (3.35") of precipitation is accumulated. In Vientiane, during the entire year, the rain falls for 118 days and collects up to 1661mm (65.39") of precipitation.

Daylight

The average length of the day in April is 12h and 33min.
On the first day of April, sunrise is at 06:03 and sunset at 18:23. On the last day of the month, sunrise is at 05:43 and sunset at 18:30 +07.

Sunshine

In Vientiane, the average sunshine in April is 7.5h.

UV index

March through September, with an average maximum UV index of 12, are months with the highest UV index. A UV Index estimate of 11, and higher, represents an excessive health risk from exposure to the Sun's UV rays for the ordinary person.
Note: In April, a daily maximum UV index of 12 leads to the following instructions:
Undertake all key precautions, as unprotected skin and eyes may get burns in no time. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Directly after swimming or an outdoor workout, generously apply and reapply a broad-spectrum SPF 30+ sunscreen.