May

It's the best period to discover the islands close to western Europe countries, before summer overwhelms them under hordes of holiday makers : Italy, Venice, Capri and Procida, Sicily, Sardinia); Greek islands, Malta (still cool weather, but quieter than later on)

italia (procida) - grece (santorin-cyclades)

The best season for the Seychelles.
The dry season ends over Senegal.
It begins on reunion Island, on Rio de Janeiro.
In the Caribbean, we are still between seasons, for me often the most pleasant period.