September weather forecast
Barthélemy, French Guiana

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Weather in September

September in Barthélemy witnesses the least amount of rainfall in the year, down to a mere 23mm (0.91"). The drastic reduction in precipitation signifies the peak of the dry spell that began in June. Despite this, Barthélemy continues to be characterized by a warm tropical climate as temperatures, humidity, and daylight hours remain high. The UV index maintains its peak position at 7, indicative of bright and sunny days. Thus, September stands out for its particularly dry weather within the overarching tropical weather pattern in Barthélemy.

Temperature

September's onset records an average high-temperature of a still tropical 31.5°C (88.7°F), a near match to August's 30.9°C (87.6°F). Barthélemy experiences an average nighttime temperature of 24.5°C (76.1°F) in the month of September.

Heat index

For September, the heat index is evaluated at an extremely hot 41°C (105.8°F). Exercise enhanced safety steps, heat cramps and heat exhaustion are probable. Heatstroke could be a result of sustained activity.
Keep in mind the heat index values are meant for areas in shade and with light wind. Exposing to direct sunshine may enhance heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', evaluates the perceived heat by adding the effect of moisture in the air. The influence of weather is personal, differing among individuals based on variations in body mass, stature, and the degree of physical exertion. 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 hold great significance to children. Children often miss understanding the importance of rest and rehydration. Thirst usually appears late during dehydration - therefore, maintaining hydration, particularly during long physical activities, is essential.
As a reaction to high temperatures, the human body begins to perspire, using the evaporation of sweat to lower its temperature. A higher relative humidity affects normal body cooling by reducing the evaporation rate, subsequently lowering the rate at which the body cools and increasing the perception of heat. Overheating and potential dehydration arise when body heat gain eclipses its release capability.

Humidity

The months with the lowest humidity are September and October, with an average relative humidity of 76%.

Rainfall

September is the month with the least rainfall. Rain falls for 12.2 days and accumulates 23mm (0.91") of precipitation.

Daylight

In Barthélemy, the average length of the day in September is 12h and 8min.
On the first day of the month, sunrise is at 06:24 and sunset at 18:35. On the last day of September, in Barthélemy, sunrise is at 06:17 and sunset at 18:22 -03.

Sunshine

September has the most sunshine of the year in Barthélemy, French Guiana, with an average of 9.2h of sunshine.

UV index

The months with the highest UV index are June through November, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health risk from unsafe exposure to UV radiation for the ordinary person.
Note: A maximum daily UV index of 7 during September morphs into the following directions:
Apply measures and align with sun safety principles. Safeguarding against skin and eye injury is pivotal. During the period from 10 a.m. to 4 p.m., UV radiation is highest. Try to avoid direct sunlight during these hours. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.

Frequently asked questions

Is it hot in Barthélemy during September?

An average high-temperature, in September, in Barthélemy, is 31.5°C (88.7°F) and the average low-temperature is 24.5°C (76.1°F). In September, the average heat index (a.k.a. 'feels like', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, is evaluated at 41°C (105.8°F).

What are the least humid months in Barthélemy?

September and October, with an average relative humidity of 76%, are the least humid months.

What is the average humidity in September in Barthélemy?

In Barthélemy, French Guiana, the average relative humidity in September is 76%.

What is the driest month in Barthélemy?

The month with the least rainfall in Barthélemy, French Guiana, is September, when the rain falls for 12.2 days and typically collects 23mm (0.91") of precipitation.

How much does it rain in Barthélemy in September?

In Barthélemy, French Guiana, in September, during 12.2 rainfall days, 23mm (0.91") of precipitation is typically accumulated.

What is the average length of the day in September in Barthélemy?

The average day length in September in Barthélemy, French Guiana, is 12h and 8min.

What time are sunrise and sunset in September in Barthélemy?

On the first day of September, sunrise is at 06:24 and sunset at 18:35. On the last day of the month, sunrise is at 06:17 and sunset at 18:22 -03.

What month has the most sunshine in Barthélemy?

The month with the most sunshine in Barthélemy is September, with an average of 9.2h of sunshine.

How many hours of sunshine does Barthélemy have in September?

In September, the average sunshine duration is 9.2h.

What is the month with the highest UV index in Barthélemy?

The months with the highest UV index are June through November, with an average maximum UV index of 7.

How high is the UV index in September in Barthélemy?

In Barthélemy, the average daily maximum UV index in September is 7. A UV Index estimate of 6 to 7 represents a high health risk from unprotected exposure to UV radiation.

Average temperature in September
Barthélemy, French Guiana

Average temperature in September - Barthélemy, French Guiana
  • Average high temperature in September: 31.5°C

The warmest month (with the highest average high temperature) is October (31.6°C).
The month with the lowest average high temperature is February (27.7°C).

  • Average low temperature in September: 24.5°C

The months with the highest average low temperature are October and November (24.8°C).
The coldest months (with the lowest average low temperature) are June and July (23.8°C).

Average pressure in September
Barthélemy, French Guiana

Average pressure in September - Barthélemy, French Guiana
  • Average pressure in September: 1012mbar

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
Barthélemy, French Guiana

Average wind speed in September - Barthélemy, French Guiana
  • Average wind speed in September: 11.1km/h

The windiest month (with the highest average wind speed) is February (12.9km/h).
The calmest month (with the lowest average wind speed) is July (8.3km/h).

Average humidity in September
Barthélemy, French Guiana

Average humidity in September - Barthélemy, French Guiana
  • Average humidity in September: 76%

The month with the highest relative humidity is May (86%).
The months with the lowest relative humidity are September and October (76%).

Average rainfall in September
Barthélemy, French Guiana

Average rainfall in September - Barthélemy, French Guiana
  • Average rainfall in September: 23mm

The wettest month (with the highest rainfall) is May (293mm).
The driest month (with the least rainfall) is September (23mm).

Average rainfall days in September
Barthélemy, French Guiana

Average rainfall days in September - Barthélemy, French Guiana
  • Average rainfall days in September: 12.2 days

The month with the highest number of rainy days is May (28.9 days).
The month with the least rainy days is October (11.6 days).

Average daylight in September /
Average sunshine in September
Barthélemy, French Guiana

Average daylight in September / Average sunshine in September - Barthélemy, French Guiana
  • Average daylight in September: 12h and 1min

The month with the longest days is June (Average daylight: 12h and 24min).
The month with the shortest days is December (Average daylight: 11h and 54min).

  • Average sunshine in September: 9h and 1min

The month with the most sunshine is September (Average sunshine: 9h and 12min).
The month with the least sunshine is February (Average sunshine: 5h and 36min).

Average sunshine days in September
Barthélemy, French Guiana

Average sunshine days in September - Barthélemy, French Guiana
  • Average sunshine days in September: 13.6 days

The month with the most sunshine days is October (16.5 days).
The month with the least sunshine days is June (0.9 days).

Average UV index in September
Barthélemy, French Guiana

Average UV index in September - Barthélemy, French Guiana
  • Average UV index in September: 7

The months with the highest UV index are June, July, August, September, October and November (UV index 7).
The months with the lowest UV index are January, February, March, April, May and December (UV index 6).

Average cloud cover in September
Barthélemy, French Guiana

Average cloud cover in September - Barthélemy, French Guiana
  • Average cloud cover in September: 25

The month with the most cloud cover is February (Cloud cover 61).
The month with the least cloud cover is September (Cloud cover 25).

Average visibility in September
Barthélemy, French Guiana

Average visibility in September - Barthélemy, French Guiana
  • Average visibility in September: 10km

The months with the highest visibility are January, February, March, August, September, October and November (10km).
The months with the lowest visibility are April, May, June, July and December (9km).

Barthélemy, French Guiana

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