May in Guantánamo averages a daily high of 31.4°C with nights around 23.5°C. Expect roughly 6.9 wet days totalling 75mm. Generally workable, with some weather to plan around.
Across the year, the best time to visit Guantánamo is December–February.
Based on GUANTANAMO BAY NAS, CU (27.9km), 1995–2024. 21 years of May data.