September weather forecast
Vientiane, Laos

September witnesses a reduction in the rainfall from 335mm in August to a more manageable 297mm 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

September's arrival in Vientiane registers an average high-temperature of a still hot 30.9°C, closely aligning with the temperature of the previous month. September nights are marked by an average temperature drop to a moderately hot 24.1°C.

Heat index

The heat index value during September is computed to be a blistering 42°C. Emphasize additional safety, risk of heat cramps and heat exhaustion is high. Continuous activity might result in heatstroke.
Thinking about the heat index, one should account for its values in shaded areas with gentle breezes. With exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', is a composite of temperature and humidity figures to convey how warm it feels. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Youngsters often neglect the necessity for rest and hydration. Thirst is a sign of advancing dehydration - thus the importance of maintaining hydration, specifically during long-lasting physical activities.
Perspiration, followed by sweat evaporation, is the human body's chief method to maintain a balanced temperature. With a lot of moisture in the air, the evaporation process is not as effective, and the body does not cool down as efficiently, creating a perception of overheating. Heat-related disorders may develop if heat gain in the body overshadows its cooling capacity, leading to elevated temperatures.

Humidity

The average relative humidity in September in Vientiane is 83%.

Rainfall

In Vientiane, in September, it is raining for 17 days, with typically 297mm of accumulated precipitation. In Vientiane, during the entire year, the rain falls for 118 days and collects up to 1661mm of precipitation.

Daylight

In Vientiane, the average length of the day in September is 12h and 14min.
On the first day of September, sunrise is at 05:55 and sunset at 18:24. On the last day of the month, sunrise is at 05:59 and sunset at 17:59 +07.

Sunshine

The average sunshine in September is 4.6h.

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 ultimate health vulnerability from unsafe exposure to UV radiation for the ordinary person.
Note: A maximum daily UV index of 12 during September morphs into the following directions:
Implement every essential safety step. Individuals with fair skin might receive burns in less than 5 minutes. Seek shade and limit direct sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation. Keep in mind that shade structures like parasols or canopies do not offer complete sun protection. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Post an outdoor workout or swimming, a broad-spectrum SPF 30+ sunscreen should be applied generously and frequently.