September weather forecast
Certitude, French Guiana

The first month of the autumn, September, is still a hot month in Certitude, French Guiana, with an average temperature ranging between min 20.5°C (68.9°F) and max 34.1°C (93.4°F).

Temperature

Certitude's weather in September indicates an average high-temperature of a still hot 34.1°C (93.4°F), nearly consistent with the 32.8°C (91°F) of August. Certitude's average nighttime temperature descends significantly from the day's peak in September, settling at a pleasant 20.5°C (68.9°F).

Heat index

The heat index value during September is estimated at a blazing hot 49°C (120.2°F). Attention: Heat exhaustion and heat cramps are quite likely. Heatstroke becomes a risk with continued exertion.
Be aware that heat index ratings are designed for shaded locations and minor breezes. Being exposed to direct sunshine might trigger a heat index increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', unifies temperature and humidity readings to offer a comprehensive feel of warmth. The experience of temperature can be subjective, varying based on the individual's activity and heat perception, influenced by factors like wind, attire, and metabolic variations. Taking into account that direct sunlight can boost the heat effect, the heat index may rise by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Young individuals usually face greater risks than adults as their sweat production is less. Also, their larger skin surface relative to their small bodies and the high heat generation due to their activity contributes to their vulnerability.
The human body normally cools itself by perspiration, as evaporated sweat carries heat away from the body. Under conditions of increased relative humidity, the evaporation rate lessens, causing the body to retain more heat than under less humid conditions. Excessive heat gain, when not shed effectively by the body, can result in increasing body temperatures and related hazards.

Humidity

The average relative humidity in September in Certitude is 74%.

Rainfall

In Certitude, during September, the rain falls for 14.3 days and regularly aggregates up to 36mm (1.42") of precipitation. Throughout the year, in Certitude, there are 265.5 rainfall days, and 1078mm (42.44") of precipitation is accumulated.

Daylight

The average length of the day in September in Certitude is 12h and 8min.
On the first day of September, sunrise is at 06:27 and sunset at 18:38. On the last day of the month, sunrise is at 06:20 and sunset at 18:25 -03.

Sunshine

The months with the most sunshine are September and October, with an average of 8.8h of sunshine.

UV index

The months with the highest UV index are August through November, with an average maximum UV index of 7. A UV Index reading of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for the average person.
Note: The maximum daily UV index, 7 in September, converts into the following recommendations:
Stand by precautions and apply sun safety measures. Evading sunburn is of great importance. Be aware that the sun's UV radiation is strongest between 10 a.m. and 4 p.m. and try to reduce direct sun exposure during this period as much as possible. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration.