Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
September
Weather in September
Temperature
Temperatures reach their maximum during September and October, recording an average high-temperature of 30.9°C (87.6°F).Heat index
During September, the heat index is appraised at a blisteringly hot 40°C (104°F). Implement more preventive measures, heat cramps and heat exhaustion are probable. Heatstroke might result from extended activity.Bear in mind that the heat index values are determined for shaded areas and light breezes. In the presence of direct sunshine, the heat index could be augmented by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', evaluates the perceived heat by adding the effect of moisture in the air. Physical activity, clothing, and metabolic variations are additional factors that impact an individual's perception of temperature. Under direct sun rays, the felt temperature might be heightened, with the heat index increasing by 15 Fahrenheit (8 Celsius) degrees. Heat index values are primarily vital for children. Children regularly disregard the necessity to rest and replenish fluids. Thirst is a late symptom of dehydration - thus, maintaining hydration, particularly during long-lasting physical activities, is essential.
The natural cooling mechanism in humans involves perspiration, where the evaporation of sweat balances out excessive warmth. In the presence of high relative humidity, the evaporation rate diminishes, resulting in the body retaining more warmth compared to dry conditions. Exceeding the body's heat disposal threshold results in a rise in body temperature and potential thermal disorders.
Humidity
September and October, with an average relative humidity of 77%, are the least humid months.Rainfall
September is the month with the least rainfall. Rain falls for 14.3 days and accumulates 29mm (1.14") of precipitation.Daylight
In September, the average length of the day in Roche Hirondelle is 12h and 9min.On the first day of September in Roche Hirondelle, sunrise is at 06:26 and sunset at 18:39. On the last day of the month, sunrise is at 06:20 and sunset at 18:25 -03.
Sunshine
With an average of 9.3h of sunshine, September has the most sunshine of the year.UV index
The months with the highest UV index in Roche Hirondelle, French Guiana, are July through November, with an average maximum UV index of 7. A UV Index value of 6 to 7 symbolizes a high health hazard from unsafe exposure to UV radiation for the average person.Note: The average daily UV index of 7 in September transforms into the following instructions:
Implement preventive steps and embrace sun safety standards. Protection from skin and eye distress is compulsory. Avoid direct Sun exposure from 10 a.m. to 4 p.m., a period when UV radiation is most intense, and remember that not all shade structures provide full protection. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the warmest month in Roche Hirondelle?
How hot does it get in Roche Hirondelle in September?
What are the least humid months in Roche Hirondelle?
What is the average humidity in September in Roche Hirondelle?
What is the driest month in Roche Hirondelle?
How many days does it rain in September in Roche Hirondelle?
How many hours of daylight does Roche Hirondelle have in September?
What time are sunrise and sunset in September in Roche Hirondelle?
What month has the most sunshine in Roche Hirondelle?
How many hours of sunshine does Roche Hirondelle have in September?
What is the month with the highest UV index in Roche Hirondelle?
What is the UV index reading in September in Roche Hirondelle?
Average temperature in September
Roche Hirondelle, French Guiana
- Average high temperature in September: 30.9°C
The warmest months (with the highest average high temperature) are September and October (30.9°C).
The month with the lowest average high temperature is February (27.5°C).
- Average low temperature in September: 24.8°C
The month with the highest average low temperature is November (25.1°C).
The coldest month (with the lowest average low temperature) is January (24.2°C).
Average pressure in September
Roche Hirondelle, French Guiana
- Average pressure in September: 1012mbar
The months with the highest atmospheric pressure are June and July (1013.1mbar).
The month with the lowest atmospheric pressure is November (1009.7mbar).
Average wind speed in September
Roche Hirondelle, French Guiana
- Average wind speed in September: 12.7km/h
The windiest month (with the highest average wind speed) is February (15.3km/h).
The calmest month (with the lowest average wind speed) is July (9.7km/h).
Average humidity in September
Roche Hirondelle, French Guiana
- Average humidity in September: 77%
The months with the highest relative humidity are February and May (84%).
The months with the lowest relative humidity are September and October (77%).
Average rainfall in September
Roche Hirondelle, French Guiana
- Average rainfall in September: 29mm
The wettest month (with the highest rainfall) is May (279mm).
The driest month (with the least rainfall) is September (29mm).
Average rainfall days in September
Roche Hirondelle, French Guiana
- Average rainfall days in September: 14.3 days
The month with the highest number of rainy days is May (29.6 days).
The months with the least rainy days are September and October (14.3 days).
Average daylight in September /
Average sunshine in September
Roche Hirondelle, 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 48min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is September (Average sunshine: 9h and 18min).
The month with the least sunshine is February (Average sunshine: 5h and 48min).
Average sunshine days in September
Roche Hirondelle, French Guiana
- Average sunshine days in September: 11.6 days
The month with the most sunshine days is October (13.2 days).
The month with the least sunshine days is May (0.6 days).
Average UV index in September
Roche Hirondelle, French Guiana
- Average UV index in September: 7
The months with the highest UV index are July, August, September, October and November (UV index 7).
The months with the lowest UV index are January, February, March, April, May, June and December (UV index 6).
Average cloud cover in September
Roche Hirondelle, French Guiana
- Average cloud cover in September: 25
The month with the most cloud cover is February (Cloud cover 59).
The month with the least cloud cover is September (Cloud cover 25).
Average visibility in September
Roche Hirondelle, French Guiana
- Average visibility in September: 10km
The months with the highest visibility are January, February, March, April, August, September, October, November and December (10km).
The months with the lowest visibility are May, June and July (9km).
