September weather forecastCayo Guillermo, Cuba
September
Weather in September
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.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Cayo Guillermo, Cuba
- Average high temperature in September: 32°C
The warmest months (with the highest average high temperature) are July and August (33°C).
The month with the lowest average high temperature is January (27°C).
- Average low temperature in September: 22°C
The months with the highest average low temperature are June, July and August (23°C).
The coldest months (with the lowest average low temperature) are January and February (17°C).
Average rainfall in September
Cayo Guillermo, Cuba
- Average rainfall in September: 160mm
The wettest month (with the highest rainfall) is October (182mm).
The driest month (with the least rainfall) is December (39mm).
Average rainfall days in September
Cayo Guillermo, Cuba
- Average rainfall days in September: 15 days
The month with the highest number of rainy days is October (16 days).
The months with the least rainy days are February and April (5 days).
Average sea temperature in September
Cayo Guillermo, Cuba
- Average sea temperature in September: 29°C
The best months for swimming (with the highest average sea temperature) are June, July, August, September and October (29°C).
The coldest months (with the lowest average sea temperature) are January, February and March (25°C).
Average daylight in September /
Average sunshine in September
Cayo Guillermo, Cuba
- Average daylight in September: 12h and 18min
The month with the longest days is June (Average daylight: 13h and 30min).
The month with the shortest days is December (Average daylight: 10h and 48min).
- Average sunshine in September: 7h
The month with the most sunshine is April (Average sunshine: 9h).
The months with the least sunshine are January, February, June, September, October, November and December (Average sunshine: 7h).
Average UV index in September
Cayo Guillermo, Cuba
- Average UV index in September: 11
The months with the highest UV index are April, May, June, July and August (UV index 12).
The month with the lowest UV index is December (UV index 6).





