September weather forecast
Port Royal, Jamaica

Moving into the month of September, Port Royal experiences a minute decline in the temperature levels, whereas the rainfall touches its zenith at 154mm (6.06"). The number of rainfall days also amplifies, totalling the highest for the year at 27.1 days. There's likewise a slope in the sea temperature, but the conditions remain comfortably warm due to its' prior accumulation during the summer months. The winds and humidity maintain their tropical course, calming the impact of the heat.

Temperature

The arrival of September sees an average high-temperature of a still hot 30.1°C (86.2°F), hardly diverging from August's 30.3°C (86.5°F). Port Royal's nights in September experience an average temperature drop to a warm 24.1°C (75.4°F).

Heat index

The heat index in September is appraised at a sweltering 38°C (100.4°F). Implement additional cautionary measures, heat cramps and heat exhaustion could occur. Prolonged activity might induce heatstroke.
Understanding the heat index involves considering values for shaded locales with light wind. Direct sunlight might cause an increase of up to 15 Fahrenheit (8 Celsius) degrees in the heat index.
Note: The heat index, also known as 'felt air temperature' or 'real feel', is found by incorporating humidity levels into the air temperature measurement. One's perception of temperature is subjective, varying based on their activity and individual heat perception, influenced by factors like wind, clothing, and metabolic variations. With the sun shining directly, it's crucial to understand that it can increase the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Young individuals usually face greater risks than adults as their sweat production is less. Also, their larger skin surface relative to their small bodies and the high heat generation due to their activity contributes to their vulnerability.
As a reaction to high temperatures, the human body begins to perspire, using the evaporation of sweat to lower its temperature. Under high air temperature coupled with high humidity (high heat index), the body's perspiration is reduced, intensifying the sensation of heat. Elevated heat gain compared to the body's release capability poses risks of dehydration and potential overheating.

Humidity

In Port Royal, the average relative humidity in September is 81%.

Rainfall

In Port Royal, Jamaica, in September, during 27.1 rainfall days, 154mm (6.06") of precipitation is typically accumulated. In Port Royal, during the entire year, the rain falls for 310.9 days and collects up to 1286mm (50.63") of precipitation.

Sea temperature

With an average sea temperature of 29.5°C (85.1°F), September is the month with the warmest seawater.
Note: Surface water temperatures ranging from 25°C (77°F) to 29°C (84.2°F) are seen as ideal and highly pleasant for extended enjoyment in all water activities.

Daylight

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

Sunshine

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

UV index

June through October, with an average maximum UV index of 7, are months with the highest UV index in Port Royal. A UV Index estimate of 6 to 7 represents a high threat to health from unsafe exposure to UV radiation for the average person.
Note: In September, a regular UV index of 7 translates into these guidelines:
Persist with safeguards and heed sun safety doctrines. Keeping sunburn at bay is of prime importance. Remember that the sun's UV radiation is strongest between 10 a.m. and 4 p.m. Make an effort to avoid direct sun exposure during these hours. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Note! Reflective surfaces like sand and water heighten the UV radiation levels.