September weather forecast
Cayo Guillermo, Cuba

As September dawns on Cayo Guillermo, a marked shift in weather patterns begins to unfold. While the temperatures of 33°C (91.4°F) to 22°C (71.6°F) still represent a warm climate, the rainfall reaches a pinnacle at 160mm (6.3"). September brings more than just precipitation to this tropical island. As daylight hours begin to decrease, the length of sunshine hours remains largely unaltered, maintaining ample opportunities for sunbathing or exploring. The arrival of October brings relief to the extensive rainy season and indicates a gradual cooling trend.

Temperature

Cayo Guillermo notes an average high-temperature of a still tropical 32°C (89.6°F) in September, hardly diverging from August. Nighttime temperature in Cayo Guillermo dips to a mean of 22°C (71.6°F) during September.

Rainfall

In Cayo Guillermo, during September, the rain falls for 15 days and regularly aggregates up to 160mm (6.3") of precipitation. In Cayo Guillermo, during the entire year, the rain falls for 125 days and collects up to 1200mm (47.24") of precipitation.

Sea temperature

June through October, with an average sea temperature of 29°C (84.2°F), are months with the warmest seawater.
Note: Water temperature between 25°C (77°F) and 29°C (84.2°F) is regarded as very warm and enjoyable by all. With these temperatures, water activities are pleasurable, without feeling uncomfortable for prolonged periods.

Daylight

In Cayo Guillermo, the average length of the day in September is 12h and 16min.
On the first day of September in Cayo Guillermo, sunrise is at 06:57 and sunset at 19:31. On the last day of the month, sunrise is at 07:06 and sunset at 19:02 CDT.

Sunshine

The months with the least sunshine are January, February, June, September through December, with an average of 7h of sunshine.

UV index

In September, the average daily maximum UV index in Cayo Guillermo is 11. A UV Index reading of 11, and higher, represents an extreme health hazard from exposure to the Sun's UV rays for the ordinary person.
Note: In September, an average UV index of 11 transforms into the following instructions:
Put into effect every essential safeguard, as unprotected skin and eyes might burn instantly. 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. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage. Directly after swimming or an outdoor workout, generously apply and reapply a broad-spectrum SPF 30+ sunscreen. Attention! UV radiation is markedly stronger with water and sand reflections.