September weather forecast
Les Trois-Îlets, Martinique

In terms of maximum temperatures, September is the year's most sweltering month with a value of 29.4°C (84.9°F). An equally high sea temperature encourages water-based activities such as snorkeling, surfing and paddleboarding. Even though rainfall remains high, daylight hours and sunshine duration start to decline after the zenith of summer. The weather pattern transition encourages a slowing down of pace and a more relaxed lifestyle as autumn approaches.

Temperature

The warmest time of the year is September, with temperatures averaging a high of 29.4°C (84.9°F) and a low of 27.3°C (81.1°F).

Heat index

For most parts of September, the heat index is appraised at a very hot 35°C (95°F). Heightened precautions are necessary, heat cramps and heat exhaustion are potential risks. Continuous activity could lead to heatstroke.
The metrics for the heat index are tailored for both shady environments and light winds. Exposure to the direct sun could elevate the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is a numerical representation of warmth when taking temperature and moisture levels into account. This effect tends to be personal, with the weather perception differing among individuals due to variations in body mass, height, and exertion. The sun, when shining directly, can have a significant impact on the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Young ones are generally at greater risk than adults due to their limited sweating ability. In addition, their large skin surface relative to their small bodies and higher heat production from their activities add to their vulnerability.
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. The body is at risk of dehydration and related complications when it fails to shed excessive heat.

Humidity

In Les Trois-Îlets, Martinique, the average relative humidity in September is 75%.

Rainfall

In Les Trois-Îlets, during September, the rain falls for 21.1 days and regularly aggregates up to 81mm (3.19") of precipitation. Throughout the year, there are 251.6 rainfall days, and 667mm (26.26") of precipitation is accumulated.

Sea temperature

The month with the warmest seawater in Les Trois-Îlets, Martinique, is September, with an average sea temperature of 29.4°C (84.9°F).
Note: Water temperature between 25°C (77°F) and 29°C (84.2°F) is perceived as agreeably warm, making all water activities enjoyable without the risk of discomfort over lengthy durations.

Daylight

In September, the average length of the day is 12h and 13min.
On the first day of September in Les Trois-Îlets, Martinique, sunrise is at 05:52 and sunset at 18:15. On the last day of the month, sunrise is at 05:53 and sunset at 17:54 AST.

Sunshine

In September, the average sunshine in Les Trois-Îlets is 10.1h.

UV index

January through December, with an average maximum UV index of 7, are months with the highest UV index in Les Trois-Îlets, Martinique. January through December, with an average maximum UV index of 7, are months with the lowest UV index in Les Trois-Îlets. A UV Index reading of 6 to 7 represents a high threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In September, a regular UV index of 7 translates into these guidelines:
Stick with precautions and abide by sun safety procedures. Evading sunburn is essential. Stay out of direct sunlight between 10 a.m. and 4 p.m., when UV radiation is most intense, and remember that not all shade structures provide complete protection. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Attention! UV radiation is markedly stronger with water and sand reflections.