September weather forecastOiapoque, Brazil

September

Weather in September

September, the first month of the autumn in Oiapoque, is also a hot month, with an average temperature varying between 33.7°C (92.7°F) and 21.8°C (71.2°F).

Temperature

Transitioning into September, Oiapoque records an average high-temperature of a still hot 33.7°C (92.7°F), almost identical to August's 32.3°C (90.1°F). During the nights in September, Oiapoque observes an average low-temperature of 21.8°C (71.2°F).

Heat index

September's mean heat index is calculated to be a burning hot 49°C (120.2°F). Stay on guard: Heat exhaustion and heat cramps are predicted. Ongoing effort can cause heatstroke.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunlight may make the heat index values climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', takes into account both air temperature and humidity to illustrate what people actually feel. The impact of temperature is individual, as people's perception of weather may change based on their body mass, height, and physical activity. Awareness of direct sun exposure is crucial as it has the potential to heighten the weather's effects, pushing up the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Youngsters often neglect the necessity for rest and hydration. Thirst is a sign of advancing dehydration - thus the importance of maintaining hydration, specifically during long-lasting physical activities.
Humans rely on perspiration as a cooling mechanism, wherein the evaporating sweat counteracts excessive warmth. Increased relative humidity interferes with body cooling by slowing the rate of evaporation, resulting in a slower body cooling rate and a heightened feeling of heat. Potential thermal conditions emerge as the body's heat gain outpaces its cooling mechanisms.

Humidity

In September, the average relative humidity is 76%.

Rainfall

September is the month with the least rainfall. Rain falls for 12.5 days and accumulates 21mm (0.83") of precipitation.

Daylight

In Oiapoque, the average length of the day in September is 12h and 8min.
On the first day of the month, sunrise is at 06:21 and sunset at 18:32. On the last day of September, sunrise is at 06:14 and sunset at 18:19 -03.

Sunshine

September has the most sunshine of the year, with an average of 8.8h of sunshine.

UV index

The months with the highest UV index are August through October, 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: In September, a daily UV index of 7 turns into the following recommendations:
Stand by precautions and apply sun safety measures. Evading sunburn is of great importance. The Sun's UV radiation is most potent between 10 a.m. and 4 p.m. Try to limit direct exposure to the Sun during this period. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.

Updated: Aug 15, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

In Oiapoque, 33.7°C (92.7°F) is the average high-temperature and 21.8°C (71.2°F) is the average low-temperature during September. The average heat index (a.k.a. 'feels like', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, in September is calculated to be 49°C (120.2°F).

The average relative humidity in September is 76%.

September is the month with the least rainfall. Rain falls for 12.5 days and accumulates 21mm (0.83") of precipitation.

In Oiapoque, Brazil, in September, during 12.5 rainfall days, 21mm (0.83") of precipitation is typically accumulated.

The average day length in September is 12h and 8min.

In September, on the first day of the month, sunrise is at 06:21 and sunset at 18:32. On the last day of the month, sunrise is at 06:14 and sunset at 18:19 -03.

With an average of 8.8h of sunshine, September has the most sunshine of the year.

In September, the average sunshine duration is 8.8h.

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

The average daily maximum UV index in September in Oiapoque is 7. A UV Index of 6 to 7 symbolizes a high health threat from exposure to the Sun's UV radiation.

Today

Tomorrow

Long-term

Year J F M A M J J A September O N D

Aug

September

Oct

Average high temperature

32.3°C

33.7°C

34.3°C

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

5.9km/h

6.4km/h

7km/h

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average daylight

Average sunshine

Average sunshine days

6.4

13.5

16.3

Average UV index

Average cloud cover

Average visibility

Average temperature in September
Oiapoque, Brazil

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
Oiapoque, Brazil

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
Oiapoque, Brazil

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
Oiapoque, Brazil

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
Oiapoque, Brazil

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
Oiapoque, Brazil

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
Oiapoque, Brazil

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: 11h and 54min).

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
Oiapoque, Brazil

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
Oiapoque, Brazil

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
Oiapoque, Brazil

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
Oiapoque, Brazil

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).