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 experiences a transition to a still warm 84°F (28.9°C) in average high-temperatures with the arrival of September, not greatly differing from August's 84.2°F (29°C). In Fajardo, the nighttime temperature shows a slight difference from the daytime high, averaging to a still moderately hot 80.8°F (27.1°C) during September.

Heat index

In September, the heat index is computed to be a hot 93.2°F (34°C). Implement heightened safety measures - risk of heat exhaustion and heat cramps is increased. Prolonged activity may result in heatstroke.
Understanding the heat index involves considering values for shaded locales with light wind. Being under direct sunlight might amplify the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', arises from combining readings of air temperature and relative moisture content. Elements such as metabolic variations, pregnancy, and physical exertion can influence one's weather perception. Consider the sun's direct rays and their impact; they can potentially increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Children frequently underestimate the necessity to rest and hydrate. Thirst is a late sign of dehydration - thus, it is vital to stay hydrated, particularly during lengthy physical exercises.

Humidity

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

Rainfall

In Fajardo, Puerto Rico, in September, it is raining for 19.6 days, with typically 1.77" (45mm) of accumulated precipitation. In Fajardo, during the entire year, the rain falls for 216 days and collects up to 21.5" (546mm) of precipitation.

Ocean temperature

With an average ocean temperature of 84.9°F (29.4°C), September is the month with the warmest seawater.
Note: For any water activity, the surface water temperatures in the range of 77°F (25°C) to 84.2°F (29°C) are deemed excellent and incredibly pleasant for longer durations.

Daylight

The average length of the day in September in Fajardo is 12h and 14min.
On the first day of September in Fajardo, 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 September, the average sunshine 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 of 6 to 7 symbolizes a high health hazard from unprotected exposure to Sun's UV rays for average individuals.
Note: The daily maximum UV index of 7 in September interprets into the following advice:
Persist in precautions and follow sun safety policies. Keeping sunburn at bay is imperative. Avoid direct exposure to the Sun between 10 a.m. and 4 p.m., the peak period for UV radiation, noting that objects like parasols or canopies might not offer complete sun protection. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Note! Reflective surfaces like sand and water heighten the UV radiation levels.