September weather forecast
Grand-Santi, French Guiana

The weather conditions in Grand-Santi during September record significant changes with the reduction in humidity levels and the steady decrease of rainfall. The lowering pressure values, at 1011.5mb, suggest a smooth climatic transition into the fall season. However, the UV Index remains at 7, indicating a potential risk to skin and eyes from UV rays. Although the weather is slightly cloud-covered, September remains special with the lowest rainfall of the year, marked at 18mm (0.71"), pointing towards drier conditions.

Temperature

The arrival of September in Grand-Santi brings an average high-temperature of a still tropical 34.3°C (93.7°F), closely following the temperature pattern of August. A pronounced dip becomes evident during the nights in September as Grand-Santi logs a consistent average temperature of 21.1°C (70°F).

Heat index

The heat index value for September is calculated to be a burning hot 51°C (123.8°F). Be cautious: Heat exhaustion along with heat cramps are predicted. Heatstroke is a possible consequence of continuous physical effort.
Given the heat index, its values are aligned with shaded sites and gentle winds. Exposing to direct sunshine may enhance heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'feels like', offers an insight into how hot it feels when we factor in moisture content. A person's impression of weather can be shaped by many aspects, among them metabolic variations, pregnancy, and levels of physical activity. When directly under the sun, the weather's impact can intensify, possibly boosting the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Juveniles are regularly less conscious of the need to recuperate and rehydrate. Thirst is a tardy symptom of dehydration - hydration, especially during lengthy physical activities, should be maintained.
The human body normally cools itself by perspiration, as evaporated sweat carries heat away from the body. In the presence of abundant moisture in the atmosphere, the cooling process through evaporation is hindered, causing the body to feel excessively warm. When heat gain surpasses the level the body can shed, body temperature begins to increase, and consequently, overheating and dehydration can occur, with varying severity.

Humidity

The average relative humidity in September is 75%.

Rainfall

September is the month with the least rainfall in Grand-Santi. Rain falls for 10.3 days and accumulates 18mm (0.71") of precipitation.

Daylight

In September, the average length of the day in Grand-Santi is 12h and 8min.
On the first day of September in Grand-Santi, sunrise is at 06:31 and sunset at 18:43. On the last day of the month, sunrise is at 06:24 and sunset at 18:29 -03.

Sunshine

With an average of 9.1h of sunshine, September has the most sunshine of the year.

UV index

The months with the highest UV index are July through November, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health risk from unprotected exposure to Sun's UV rays for average individuals.
Note: A typical high UV index of 7 in September suggests the following recommendations:
Ward off overexposure. Defence against solar harm is crucial. The Sun's UV radiation is at its strongest between the hours of 10 a.m. and 4 p.m. Minimize direct exposure to the sun during this period. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.