September weather forecast
L'Observatoire, French Guiana

September, the first month of the autumn in L'Observatoire, is also a hot month, with temperature in the range of an average high of 34.4°C (93.9°F) and an average low of 21.3°C (70.3°F).

Temperature

The arrival of September sees a recorded average high-temperature of a still hot 34.4°C (93.9°F), showing little divergence from the previous month's conditions. With a notable disparity from daily peak temperatures, the average low-temperature settles at an agreeable 21.3°C (70.3°F) throughout September.

Heat index

For most parts of September, the heat index is estimated at a life-threatening hot 51°C (123.8°F). Stay alert: Heat cramps and heat exhaustion are expected. Heatstroke is a likely outcome of ongoing activity.
Take note of the fact that heat index values are based on shaded circumstances with light airflows. The heat index can potentially augment by 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. This effect is subjective, differing among individuals based on their physical activity and perception of heat, which can be influenced by factors like wind, clothing, and metabolic variances. In the direct sunlight, the weather's impact can be amplified, possibly boosting the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Younglings are generally more in peril than adults due to their reduced perspiration. Coupled with a larger skin surface relative to their tiny bodies and greater heat production because of their activity, they become more at risk.
Perspiring is a crucial mechanism for the human body, allowing it to release excessive warmth through evaporating sweat. When air moisture content is high, the cooling process through evaporation is not as efficient, leading to an ineffective body cooling process and a feeling of overheating. Excessive heat that's not properly managed leads to increased body temperatures and resultant health issues.

Humidity

The average relative humidity in September is 75%.

Rainfall

In September, in L'Observatoire, French Guiana, the rain falls for 10.3 days. Throughout September, 28mm (1.1") of precipitation is accumulated. Throughout the year, in L'Observatoire, there are 259.3 rainfall days, and 898mm (35.35") of precipitation is accumulated.

Daylight

The average length of the day in September is 12h and 8min.
On the first day of September in L'Observatoire, French Guiana, sunrise is at 06:29 and sunset at 18:41. On the last day of the month, sunrise is at 06:23 and sunset at 18:28 -03.

Sunshine

With an average of 9.2h of sunshine, September has the most sunshine of the year.

UV index

July through November, with an average maximum UV index of 7, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health hazard from unsafe exposure to UV radiation for ordinary individuals.
Note: A typical high UV index of 7 in September suggests the following recommendations:
Conform to measures and uphold sun safety traditions. Warding off skin and eye harm is necessary. 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. Experience reduced UV exposure by about half when donning a wide-brim hat.