September weather forecast
Port-au-Prince, Haiti

A stack of structures on a hillside in Port-au-Prince, Haiti
A stack of structures on a hillside in Port-au-Prince, Haiti

Weather in September

September, the first month of the autumn, in Port-au-Prince, is still a warm month, with average temperature fluctuating between 21.3°C (70.3°F) and 29.8°C (85.6°F).

Temperature

In Port-au-Prince, the average high-temperature in September is practically the same as in August - a warm 29.8°C (85.6°F). In September, the average low-temperature is 21.3°C (70.3°F).

Heat index

The average heat index is appraised at a sweltering 36.3°C (97.3°F). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like', 'real feel', 'apparent temperature', or 'felt air temperature', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. This effect is individual, with diverse people perceiving weather differently for numerous reasons (pregnancy, clothing, metabolic differences), and activity. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.
The human body normally cools itself by perspiration, as evaporated sweat carries heat away from the body. 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. When heat gain exceeds the level the body can remove, body temperature begins to rise, and heat-related illnesses and disorders may develop.

Humidity

The average relative humidity in September is 77%.

Rainfall

In Port-au-Prince, during September, the rain falls for 22.4 days and regularly aggregates up to 135mm (5.31") of precipitation. Throughout the year, there are 227.4 rainfall days, and 904mm (35.59") of precipitation is accumulated.

Sea temperature

The month with the warmest seawater is September, with an average sea temperature of 29.8°C (85.6°F).
Note: Water temperature between 25°C (77°F) and 29°C (84.2°F) is regarded as very warm and enjoyable by all. With these temperatures, water activities are pleasurable, without feeling uncomfortable for prolonged periods.

Daylight

The average length of the day in Port-au-Prince is 12.2h.

Sunshine

In Port-au-Prince, the average sunshine is 9.6h.

UV index

January through May, July through December, with an average maximum UV index of 6, are months with the lowest UV index. A UV Index estimate of 6 to 7 represents a high health risk from unprotected exposure to the Sun's UV rays for the ordinary person.
Note: In September, the average maximum UV index of 6 translate into the following recommendations:
Take precautions against overexposure. Protection against sun damage is needed. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Beware! The reflection of water and sand dramatically increases exposure to the UV rays.
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FAQ

What is the temperature in September in Port-au-Prince?

The average high-temperature, in September, in Port-au-Prince, is 29.8°C (85.6°F), while the average low-temperature is 21.3°C (70.3°F). In September, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which factors the actual air temperature with the relative humidity, is appraised at 36.3°C (97.3°F).

What is the average humidity in September in Port-au-Prince?

The average relative humidity in September in Port-au-Prince is 77%.

How much does it rain in Port-au-Prince in September?

In September, in Port-au-Prince, the rain falls for 22.4 days. Throughout September, 135mm (5.31") of precipitation is accumulated.

What month is the sea warmest in Port-au-Prince?

September is the month with the warmest seawater in Port-au-Prince, Haiti, with an average sea temperature of 29.8°C (85.6°F).

What is the water temperature in September in Port-au-Prince?

In Port-au-Prince, Haiti, the average seawater temperature in September is 29.8°C (85.6°F). For swimming, diving, and other water activities, temperatures between 25°C (77°F) and 29°C (84.2°F) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

What is the average length of the day in September in Port-au-Prince?

The average length of the day in September in Port-au-Prince is 12.2h.

How many hours of sunshine does Port-au-Prince have in September?

In September, the average sunshine is 9.6h.

What is the month with the lowest UV index in Port-au-Prince?

Months with the lowest UV index are January through May, July through December, with an average maximum UV index of 6.

What is the UV index reading in September in Port-au-Prince?

In Port-au-Prince, the average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health vulnerability from the exposure to the Sun's UV rays.

Average temperature in September
Port-au-Prince, Haiti

Average temperature in September - Port-au-Prince, Haiti
  • Average high temperature in September: 29.8°C

The warmest month (with the highest average high temperature) is August (30.9°C).
The month with the lowest average high temperature is January (27.6°C).

  • Average low temperature in September: 21.3°C

Months with the highest average low temperature are August and September (21.3°C).
The coldest month (with the lowest average low temperature) is January (18.2°C).

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Average pressure in September
Port-au-Prince, Haiti

Average pressure in September - Port-au-Prince, Haiti
  • Average pressure in September: 1013.2mbar

The month with the highest atmospheric pressure is January (1016.3mbar).
The month with the lowest atmospheric pressure is October (1012.5mbar).

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Average wind speed in September
Port-au-Prince, Haiti

Average wind speed in September - Port-au-Prince, Haiti
  • Average wind speed in September: 6.5km/h

The windiest month (with the highest average wind speed) is June (9.2km/h).
The calmest month (with the lowest average wind speed) is September (6.5km/h).

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Average humidity in September
Port-au-Prince, Haiti

Average humidity in September - Port-au-Prince, Haiti
  • Average humidity in September: 77%

The month with the highest relative humidity is November (80%).
The month with the lowest relative humidity is February (72%).

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Average rainfall in September
Port-au-Prince, Haiti

Average rainfall in September - Port-au-Prince, Haiti
  • Average rainfall in September: 135mm

The wettest month (with the highest rainfall) is May (141mm).
The driest month (with the least rainfall) is January (12mm).

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Average rainfall days in September
Port-au-Prince, Haiti

Average rainfall days in September - Port-au-Prince, Haiti
  • Average rainfall days in September: 22.4 days

Months with the highest number of rainy days are April and October (24.4 days).
The month with the least rainy days is January (9.9 days).

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Average sea temperature in September
Port-au-Prince, Haiti

Average sea temperature in September - Port-au-Prince, Haiti
  • Average sea temperature in September: 29.8°C

The best month for swimming (with the highest average sea temperature) is September (29.8°C).
The coldest month (with the lowest average sea temperature) is February (26.8°C).

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Average daylight in September /
Average sunshine in September
Port-au-Prince, Haiti

Average daylight in September / Average sunshine in September - Port-au-Prince, Haiti
  • Average daylight in September: 12.2h

The month with the longest days is June (Average daylight: 13.2h).
The month with the shortest days is December (Average daylight: 11h).

  • Average sunshine in September: 9.6h

The month with the most sunshine is July (Average sunshine: 11.3h).
The month with the least sunshine is February (Average sunshine: 7.2h).

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Average sunshine days in September
Port-au-Prince, Haiti

Average sunshine days in September - Port-au-Prince, Haiti
  • Average sunshine days in September: 4.7 days

The month with the most sunshine days is December (19 days).
The month with the least sunshine days is April (3.3 days).

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Average UV index in September
Port-au-Prince, Haiti

Average UV index in September - Port-au-Prince, Haiti
  • Average UV index in September: 6

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

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Average cloud cover in September
Port-au-Prince, Haiti

Average cloud cover in September - Port-au-Prince, Haiti
  • Average cloud cover in September: 27

The month with the most cloud cover is April (Cloud cover 35).
The month with the least cloud cover is December (Cloud cover 21).

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Average visibility in September
Port-au-Prince, Haiti

Average visibility in September - Port-au-Prince, Haiti
  • Average visibility in September: 9km

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

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