September weather forecast
Vientiane, Laos

September witnesses a reduction in the rainfall from 335mm (13.19") in August to a more manageable 297mm (11.69") in Vientiane, Laos. This drop in rainfall comes with a slight decrease in temperatures and relative humidity. The weather signals the impending arrival of the cooler months, which citizens anticipate eagerly. The change in weather also ushers in the season of harvest, a significant and joyous occasion in Laos.

Temperature

The commencement of September in Vientiane introduces an average high-temperature of a still tropical 30.9°C (87.6°F), closely mirroring the preceding month. Vientiane, in September, experiences an average temperature of 24.1°C (75.4°F) at night.

Heat index

For most parts of September, the heat index is computed to be a blistering 42°C (107.6°F). Incorporate additional safety actions, heat cramps and heat exhaustion are possible. Long-term activity may induce heatstroke.
When assessing, remember that heat index measurements are for light winds and shaded spots. When exposed to the direct sun, the heat index may augment by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', is a single figure representing how weather conditions feel when combining temperature and humidity. An individual's perception of weather can be affected by a variety of elements including metabolic differences, being pregnant, and their level of physical exertion. Take note that direct exposure to the sun can increase the felt temperature, possibly adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are extremely vital to babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it's vital to remain hydrated, particularly during prolonged physical activities.
When the body gets too warm, it perspires, leading to sweat evaporation which cools it down. When the level of relative humidity is elevated, evaporation diminishes, causing more warmth to be retained in the body than in dry air. When heat uptake goes beyond the body's cooling mechanisms, there's a surge in body temperature, posing health risks.

Humidity

The average relative humidity in September is 83%.

Rainfall

In September, in Vientiane, the rain falls for 17 days. Throughout September, 297mm (11.69") of precipitation is accumulated. Throughout the year, there are 118 rainfall days, and 1661mm (65.39") of precipitation is accumulated.

Daylight

In Vientiane, the average length of the day in September is 12h and 14min.
On the first day of the month, sunrise is at 05:55 and sunset at 18:23. On the last day of September, in Vientiane, sunrise is at 05:59 and sunset at 17:59 +07.

Sunshine

In Vientiane, Laos, the average sunshine in September is 4.6h.

UV index

The months with the highest UV index are March through September, with an average maximum UV index of 12. A UV Index of 11, and more, symbolizes an extreme health hazard from unsafe exposure to UV radiation for the ordinary person.
Note: The maximum UV index of 12 during September leads to these instructions:
Implement every essential safety step. Individuals with fair skin might receive burns in less than 5 minutes. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Apply liberally and reapply a broad-spectrum sunscreen of SPF 30+ every two hours, and promptly after any outdoor workout or a swim.