For much of the year the Cayo Guillermo weather is very warm and dry, boasting sea temperatures that range from 25-30 degrees Celsius.

When there is rain, the temperature drops slightly despite the months of May to September being the warmest months. However, rainfall hardly ever lasts for long periods of time. Showers tend to be quite short for the most part.

The area has light breezes which takes the edge of the high summer humidity levels.

The below table shows Cayo Guillermo weather averages throughout the year.