September weather forecast
Portmore, Jamaica

September ushers in a minor drop in temperature in Portmore, Jamaica, preparing the city for the approaching autumn season. Comparative to August, it experiences an increase in rainfall of approximately 154mm (6.06"), making the city significantly wet. The relatively lower temperatures, steady wind, and high humidity balance the weather conditions, maintaining a comfortable climate. With the sea temperature remaining pleasant, beach activities continue to be enjoyable. Despite recurrent showers, the city presents a captivating blend of sunny skies and tropical rains.

Temperature

The advent of September presents an average high-temperature of a still tropical 30.1°C (86.2°F), maintaining a close correlation with the preceding month. Portmore's nighttime temperature in September falls to an average of 24.1°C (75.4°F).

Heat index

The heat index in September is appraised at a sweltering 38°C (100.4°F). Use additional protective measures, heat cramps and heat exhaustion are possible outcomes. Continuous activity might lead to heatstroke.
Heat index's context suggests values are appropriate for shady areas and slight breezes. Exposure to the direct sun could elevate the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', binds temperature metrics with humidity values to give a sense of the actual warmth. Elements such as metabolic variations, pregnancy, and physical exertion can shape one's weather perception. Direct exposure to the sun's rays can enhance the felt temperature, increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Youngsters generally face more threats than adults given their lesser ability to sweat. Coupled with their larger skin surface relative to their small bodies and higher heat production due to their activities, they are more endangered.
The physiological response of the human body to excess warmth is to perspire, thereby cooling itself through sweat evaporation. Relative humidity in excess curtails evaporation, therefore reducing heat dissipation from the body, leading to feelings of excess heat. Overheating risks increase with rising body temperatures, especially if heat release isn't efficient.

Humidity

In September, the average relative humidity in Portmore, Jamaica, is 81%.

Rainfall

In Portmore, during September, the rain falls for 27.1 days and regularly aggregates up to 154mm (6.06") of precipitation. Throughout the year, in Portmore, there are 310.9 rainfall days, and 1286mm (50.63") of precipitation is accumulated.

Sea temperature

With an average sea temperature of 29.5°C (85.1°F), September is the month with the warmest seawater.
Note: Water temperatures between 25°C (77°F) and 29°C (84.2°F) are ideal for all water activities, offering enjoyment without causing discomfort over extended periods.

Daylight

The average length of the day in September in Portmore is 12h and 14min.
On the first day of September in Portmore, sunrise is at 05:53 and sunset at 18:21. On the last day of the month, sunrise is at 05:57 and sunset at 17:56 EST.

Sunshine

August and September, with an average of 10.8h of sunshine, are months with the most sunshine in Portmore.

UV index

The months with the highest UV index in Portmore are June through October, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high threat to health from unsafe exposure to UV radiation for the ordinary person.
Note: The daily high UV index of 7 during September translates into the following recommendations:
Persist with safeguards and heed sun safety doctrines. Keeping sunburn at bay is of prime importance. Stay out of direct sunlight and seek shade between 10 a.m. and 4 p.m., when UV radiation is strongest, but remember that shade devices may not offer full sun protection. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays. Warning! The Sun's UV rays intensify with reflections from sand and water.