May weather forecast
Cayo Guillermo, Cuba

Mingling the last fragments of spring with the onset of summer, May sets a differing tone weather-wise in Cayo Guillermo. Now reaching its peak, rainfall hits 168mm (6.61"), the highest level of precipitation thus far in the year. Prolonged daylight hours and a high UV index continue to define the daytime climate. Despite the substantial rainfall, temperatures remain warm, catalyzing the island's lush flora. As May rolls into June, the residents and visitors brace themselves for the peak summer weather.

Temperature

May's advent notes a subtle adjustment in average high-temperature to a still tropical 31°C (87.8°F) from April. The nighttime temperature, during May, averages of 21°C (69.8°F).

Rainfall

In Cayo Guillermo, in May, it is raining for 12 days, with typically 168mm (6.61") of accumulated precipitation. Throughout the year, there are 125 rainfall days, and 1200mm (47.24") of precipitation is accumulated.

Sea temperature

In Cayo Guillermo, in May, the average water temperature is 27°C (80.6°F).
Note: Swimming, diving, and other water endeavors at temperatures between 25°C (77°F) and 29°C (84.2°F) are considered enjoyable and satisfying for extended periods without discomfort.

Daylight

The average length of the day in May is 13h and 14min.
On the first day of May in Cayo Guillermo, sunrise is at 06:41 and sunset at 19:41. On the last day of the month, sunrise is at 06:29 and sunset at 19:55 CDT.

Sunshine

In Cayo Guillermo, the average sunshine in May is 8h.

UV index

The months with the highest UV index are April through August, with an average maximum UV index of 12. A UV Index value of 11, and more, symbolizes an excessive health risk from unprotected exposure to Sun's UV rays for average individuals.
Note: In May, a daily UV index of 12 turns into the following recommendations:
Ensure all key precautions. Defense against sun exposure is critical. Limit your direct sun exposure, especially between 10 a.m. and 4 p.m., when UV radiation is strongest. Shade structures might not provide complete sun protection. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays. Sunscreen of at least SPF 30 should be applied generously and reapplied often on overcast days, especially post swim or outdoor exercise. Take caution! The UV rays from the Sun gain strength from sand and water reflections.