September weather forecastSiminiout, French Guiana
September
Weather in September
The first month of the autumn, September, is still a tropical month in Siminiout, French Guiana, with an average temperature fluctuating between 33.7°C (92.7°F) and 21.8°C (71.2°F).Temperature
In Siminiout, September's average high-temperature stands at a still hot 33.7°C (92.7°F), closely related to the preceding month. Siminiout experiences an average temperature drop to an agreeable 21.8°C (71.2°F) during September nights.Heat index
The heat index value for September is appraised at a blazing hot 49°C (120.2°F). Stay alert: Heat cramps and heat exhaustion are expected. Heatstroke is a likely outcome of ongoing activity.Bear in mind that the heat index values are determined for shaded areas and light breezes. The heat index could experience an increase of 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'apparent temperature' or 'feels like', is a metric representing the sensation of warmth when air temperature and moisture come together. The effect is experienced differently by individuals, hinging on unique characteristics such as body mass, stature, and level of activity. Should you be directly under the sun, anticipate a possible increase in the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to babies and toddlers. Young people are generally more susceptible than adults because they perspire less. Furthermore, their proportionally larger skin surface to their petite bodies and the increased heat output from their actions add to the risk.
Normally, the human body cools itself through perspiration, which removes excessive heat by evaporating sweat. In the presence of high relative humidity, the evaporation rate diminishes, resulting in the body retaining more warmth compared to dry conditions. When the heat gained surpasses the body's cooling capacity, temperatures rise, signaling potential health concerns.
Humidity
In Siminiout, the average relative humidity in September is 76%.Rainfall
The month with the least rainfall in Siminiout is September, when the rain falls for 12.5 days and typically collects 21mm (0.83") of precipitation.Daylight
The average length of the day in September is 12h and 8min.On the first day of September in Siminiout, sunrise is at 06:26 and sunset at 18:36. On the last day of the month, sunrise is at 06:18 and sunset at 18:23 -03.
Sunshine
With an average of 8.8h of sunshine, September has the most sunshine of the year in Siminiout, French Guiana.UV index
August through October, with an average maximum UV index of 7, are months with the highest UV index in Siminiout. A UV Index of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV radiation for the average person.Note: A maximum high daily UV index of 7 during September translates into the following directions:
Ward off overexposure. Defence against solar harm is crucial. The Sun emits the most powerful UV radiation between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Siminiout, French Guiana
- Average high temperature in September: 33.7°C
The warmest month (with the highest average high temperature) is October (34.3°C).
The month with the lowest average high temperature is February (27.9°C).
- Average low temperature in September: 21.8°C
The month with the highest average low temperature is April (22.4°C).
The coldest month (with the lowest average low temperature) is July (21.3°C).
Average pressure in September
Siminiout, French Guiana
- Average pressure in September: 1012.1mbar
The month with the highest atmospheric pressure is July (1013.2mbar).
The month with the lowest atmospheric pressure is November (1009.8mbar).
Average wind speed in September
Siminiout, French Guiana
- Average wind speed in September: 6km/h
The windiest month (with the highest average wind speed) is October (6.1km/h).
The calmest month (with the lowest average wind speed) is June (4.2km/h).
Average humidity in September
Siminiout, French Guiana
- Average humidity in September: 76%
The month with the highest relative humidity is May (91%).
The month with the lowest relative humidity is October (75%).
Average rainfall in September
Siminiout, French Guiana
- Average rainfall in September: 21mm
The wettest month (with the highest rainfall) is May (195mm).
The driest month (with the least rainfall) is September (21mm).
Average rainfall days in September
Siminiout, French Guiana
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is May (28.9 days).
The month with the least rainy days is October (12 days).
Average daylight in September /
Average sunshine in September
Siminiout, French Guiana
- Average daylight in September: 12h and 6min
The month with the longest days is June (Average daylight: 12h and 18min).
The month with the shortest days is December (Average daylight: 12h and 0min).
- Average sunshine in September: 8h and 48min
The month with the most sunshine is September (Average sunshine: 8h and 48min).
The month with the least sunshine is February (Average sunshine: 4h and 0min).
Average sunshine days in September
Siminiout, French Guiana
- Average sunshine days in September: 13.5 days
The month with the most sunshine days is October (16.3 days).
The month with the least sunshine days is May (1.8 days).
Average UV index in September
Siminiout, French Guiana
- Average UV index in September: 7
The months with the highest UV index are August, September and October (UV index 7).
The months with the lowest UV index are January, February, March, April, May, June, July, November and December (UV index 6).
Average cloud cover in September
Siminiout, French Guiana
- Average cloud cover in September: 48
The month with the most cloud cover is February (Cloud cover 78).
The month with the least cloud cover is October (Cloud cover 46).
Average visibility in September
Siminiout, French Guiana
- Average visibility in September: 7km
The months with the highest visibility are September and October (7km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, November and December (6km).
