September weather forecast
Fajardo, PR

As Fajardo moves into September, the temperatures still maintain a higher register, both on land and at sea. Albeit, a marginal dip in daily sunlight hours is observed, compared to the preceding summer months. Being a transitional month, September does bring quite a bit of rainfall, marking about 19.6 days of rainfall that adds up to 1.77in in total. Severe weather conditions remain largely off the radar, leaving behind extended warm, dry periods that make sightseeing, beach visits, and water sports rather enjoyable.

Temperature

Fajardo ushers in September with an average high-temperature of a still warm 84°F (28.9°C), showing a close resemblance to the previous month. In Fajardo, September nights maintain a consistent temperature, with an average low of 80.8°F (27.1°C).

Heat index

September's average heat index is evaluated at a tropical 93.2°F (34°C). Emphasize additional safety, risk of heat cramps and heat exhaustion is high. Continuous activity might result in heatstroke.
When assessing, remember that heat index measurements are for light winds and shaded spots. The direct sun can potentially cause the heat index to increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', is an estimation of the warmth sensation when considering humidity levels. 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. 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 primarily vital for children. Youngsters typically face more danger than adults since they sweat less. Their larger skin surface compared to their small bodies and heightened heat production from their activities augment their vulnerability.

Humidity

In Fajardo, the average relative humidity in September is 78%.

Rainfall

In September, the rain falls for 19.6 days. Throughout September, 1.77" (45mm) of precipitation is accumulated. In Fajardo, during the entire year, the rain falls for 216 days and collects up to 21.5" (546mm) of precipitation.

Ocean temperature

September is the month with the warmest seawater, with an average ocean temperature of 84.9°F (29.4°C).
Note: Ideal surface water temperatures for any water activity fall between 77°F (25°C) and 84.2°F (29°C), offering maximum enjoyment for lengthened periods.

Daylight

In Fajardo, Puerto Rico, the average length of the day in September is 12h and 14min.
On the first day of September, sunrise is at 6:08 am and sunset at 6:36 pm. On the last day of the month, sunrise is at 6:12 am and sunset at 6:11 pm AST.

Sunshine

In Fajardo, the average sunshine in September is 9.1h.

UV index

January, March through December, with an average maximum UV index of 7, are months with the highest UV index. A UV Index reading of 6 to 7 represents a high health risk from unsafe exposure to UV radiation for ordinary individuals.
Note: A maximum high UV index of 7 in September translates into the following recommendations:
Escape overexposure. People with light skin may incur burns in fewer than 20 minutes. Avoid direct Sun exposure and stay in the shade between 10 a.m. and 4 p.m., a time when UV radiation is most intense, noting that not all shade structures offer full protection. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck. Beware! The reflection of water and sand dramatically increases exposure to the UV rays.