September weather forecast
Saint-Marc, Haiti

As autumn approaches, September brings a cool-down in temperature and sea temperature from its peak in August in Saint-Marc. On the contrary, rainfall slightly rises to 101mm (3.98"), marking September as the month with the second-highest rainfall. With fewer daylight hours and fewer sunshine days, the weather in September can be unpredictable, making it ideal for those looking to experience the variety of Saint-Marc’s tropical climate.

Temperature

September's commencement is accompanied by an average high-temperature of a warm 29.8°C (85.6°F), diverging marginally from August's 30.4°C (86.7°F). Nighttime temperatures in Saint-Marc, Haiti, consistently average a still moderately hot 23.1°C (73.6°F) during September.

Heat index

The heat index value for September is estimated at a sweltering 37°C (98.6°F). Additional precautions are required to avert heat cramps and heat exhaustion. Persistent activity may culminate in heatstroke.
When referencing the heat index, its values are suitable for shady environments and light breezes. If directly exposed to the sun, the heat index could rise by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. This effect is subjective, differing among individuals based on their physical activity and perception of heat, which can be influenced by factors like wind, clothing, and metabolic variances. It is essential to realize that direct sunlight can escalate the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it's vital to remain hydrated, particularly during prolonged physical activities.
Evaporating sweat, thanks to perspiration, acts as a natural air conditioner for the human body. With a high level of moisture in the air, the evaporation process becomes less efficient, preventing the body from cooling down efficiently and resulting in a sensation of overheating. Heat disorders may be on the horizon when body temperatures rise from inadequate heat management.

Humidity

In Saint-Marc, the average relative humidity in September is 79%.

Rainfall

In September, in Saint-Marc, the rain falls for 23.6 days. Throughout September, 101mm (3.98") of precipitation is accumulated. In Saint-Marc, during the entire year, the rain falls for 219.6 days and collects up to 736mm (28.98") of precipitation.

Sea temperature

September is the month with the warmest seawater in Saint-Marc, Haiti, with an average sea temperature of 29.9°C (85.8°F).
Note: Water temperature between 25°C (77°F) and 29°C (84.2°F) provides warmth and pleasure, making water activities enjoyable for lengthened periods without feeling uncomfortable.

Daylight

In September, the average length of the day is 12h and 14min.
On the first day of September, sunrise is at 06:35 and sunset at 19:05. On the last day of the month, sunrise is at 06:41 and sunset at 18:39 EDT.

Sunshine

In September, the average sunshine is 10.1h.

UV index

The months with the highest UV index are April through September, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health risk from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: The maximum UV index of 7 during September leads to these instructions:
Resist extreme sun exposure. Guarding against solar damage is essential. Between 10 a.m. and 4 p.m., the Sun emits the most powerful UV radiation. Limit direct exposure to the Sun during these hours. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Note! Reflective surfaces like sand and water heighten the UV radiation levels.