September weather forecast
Bienvenue, French Guiana

The city of Bienvenue ushers in the month of September with a relative dryness, characterized by a further drop in rainfall to a mere 21mm (0.83"). The gradual decrease in cloud coverage uncloaks the sun, exposing the city to increased periods of sunlight. While temperatures moderate slightly, humidity levels reach their lowest, contributing to a less sticky atmosphere. A gentle increase in wind speed from August adds a refreshing touch to the overall weather.

Temperature

Bienvenue sees the arrival of September with an average high-temperature of a still tropical 33.7°C (92.7°F), indicating a subtle variation from August. During September, Bienvenue observes a consistent average nighttime temperature of 21.8°C (71.2°F).

Heat index

Throughout September, the heat index is computed to be a blazing hot 49°C (120.2°F). Forewarned: Heat cramps and heat exhaustion are anticipated. Ongoing physical activity increases the likelihood of heatstroke.
Remember that heat index calculations are made for conditions in the shade with light wind. Exposure to the direct sun could elevate the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. The individual's impression of temperature can be affected by numerous factors such as metabolic variations, physical exertion, and attire. Realize that direct exposure to sunlight can augment the felt heat, leading to a potential increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Young kids are often more at risk than adults as they tend to perspire less. Besides, their skin surface is larger relative to their small bodies, and their increased heat output from their active lifestyle compounds their risk.
In the face of high temperatures, the human body's reflex is to perspire, leveraging sweat evaporation for cooling. An elevated level of relative humidity hinders evaporation, leading to decreased heat elimination from the body, inducing a sensation of excess heat. As the body gains more heat than it can dissipate, there's a risk of increasing temperatures and resultant overheating.

Humidity

In Bienvenue, the average relative humidity in September is 76%.

Rainfall

The month with the least rainfall in Bienvenue, French Guiana, is September, when the rain falls for 12.5 days and typically collects 21mm (0.83") of precipitation.

Daylight

In Bienvenue, French Guiana, the average length of the day in September is 12h and 8min.
On the first day of the month, sunrise is at 06:25 and sunset at 18:35. On the last day of September, sunrise is at 06:17 and sunset at 18:23 -03.

Sunshine

With an average of 8.8h of sunshine, September has the most sunshine of the year in Bienvenue, French Guiana.

UV index

The months with the highest UV index are August through October, with an average maximum UV index of 7. A UV Index reading of 6 to 7 represents a high health hazard from exposure to the Sun's UV radiation for the average person.
Note: The maximum UV index, 7 during September, leads to the following recommendations:
Refrain from overexposure. Fair-skinned individuals could burn in under 20 minutes. Try to minimize direct Sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation. Also note that objects like parasols or canopies might not provide complete sun protection. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.