Hordes of tourists visit the Italian seaside with dreams of dipping into cobalt-blue waters and sunbathing for hours under glorious skies. Only one thing can spoil those idyllic holiday plans: rain.

But beginning this month, the Italian island of Elba, off the coast of Tuscany, started offering tourists an unexpected guarantee: Hotels will refund guests if it rains.

Elba, the largest island in the Tuscan Archipelago, is perhaps best known as the place where Napoleon spent almost 10 months in exile more than two centuries ago. The island started the good-weather initiative, called “Elba No Rain,” this year: Guests receive a refund for one night if it rains for more than two hours on any given day during their stay.

If it rains every day for more than two hours at a time, then the whole stay will be free.

The offer isn’t entirely new — a few hotels on the island already had similar initiatives in place — but encouraging all of the hotels on Elba to make the guarantee is intended “to minimize commercial damage due to weather forecasts,” Claudio Della Lucia, an associate tourism manager for the island, said in an email on Sunday.