September weather forecast
Punta Santiago, PR

By September, the weather in Punta Santiago begins to cool down slightly, heralding the slow transition towards the fall season. The overall temperature displays a marginal decrease and rainfall begins to drop. A decrease in wind speed is also noticeable. However, despite the weather changes, humidity remains consistent with the summer months. Even though temperatures remain high at 84.6°F (29.2°C), the sea temperatures begin to cool down, somewhat moderating the weather, and rainfall decreases to 4.33" (110mm) over approximately 24.5 days.

Temperature

As Punta Santiago steps into September, the average high-temperature holds at a still warm 84.6°F (29.2°C), hinting at a minor fluctuation from the prior month. Punta Santiago's September nights experience a subtle temperature dip to an average of 78.6°F (25.9°C).

Heat index

For most parts of September, the heat index is estimated at a torrid 95°F (35°C). Undertake extra safety actions, heat cramps and heat exhaustion are expected. Heatstroke may result from lengthy activity.
In terms of the heat index, values are set with light wind and shade conditions in mind. Uninterrupted exposure to the sun may boost the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'real feel', comes about by integrating the temperature readings with the humidity levels. 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. Given direct exposure to sunlight, one might experience a rise in the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly important for children. Young individuals are generally in more danger than adults due to their lower capacity to sweat. Moreover, their large skin surface in relation to their small bodies and the increased heat generation from their activities makes them more vulnerable.
Sweat evaporation plays a crucial role in cooling the human body, a process enabled by perspiration. With high air temperature and humidity (high heat index) conditions, sweat production is restricted, leading to an amplified perception of heat. As the body gains more heat than it can dissipate, there's a risk of increasing temperatures and resultant overheating.

Humidity

In September, the average relative humidity is 79%.

Rainfall

In September, in Punta Santiago, the rain falls for 24.5 days. Throughout September, 4.33" (110mm) of precipitation is accumulated. Throughout the year, there are 268.8 rainfall days, and 38.58" (980mm) of precipitation is accumulated.

Ocean temperature

The month with the warmest seawater is September, with an average ocean temperature of 84.9°F (29.4°C).
Note: Engaging in water activities, such as swimming or diving, in temperatures from 77°F (25°C) to 84.2°F (29°C) is very pleasurable for extended periods, without any discomfort.

Daylight

In September, the average length of the day is 12h and 14min.
On the first day of the month, sunrise is at 6:08 am and sunset at 6:36 pm. On the last day of September, sunrise is at 6:13 am and sunset at 6:12 pm AST.

Sunshine

In Punta Santiago, the average sunshine in September is 9.1h.

UV index

The months with the highest UV index in Punta Santiago are April through December, with an average maximum UV index of 7. A UV Index estimate of 6 to 7 represents a high health hazard from exposure to the Sun's UV rays for the ordinary person.
Note: The UV index of 7 during September leads to these advisories:
Evade overexposure. Individuals with fair skin risk burning in under 20 minutes. Try to minimize direct Sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation. Also note that objects like parasols or canopies might not provide complete sun protection. Employ a hat with a wide brim for robust protection, cutting UV exposure by half. Be attentive! The UV exposure is heightened with reflections from sand and water.