Sunny Beach weather in May

We have long wanted to visit Bulgaria, and when choosing a place for a trip, we chose Sunny Beach, probably one of the largest resorts in this country, with a long beach. The choice of the resort can be called correct, but with the month, we made a slight mistake. The beginning of May for a beach holiday turned out to be quite cold. And if during the day, when the Sun warmed the air, it became warm enough for walking, then with the arrival of evening the temperature dropped sharply by ten degrees, and it became completely cold. And, of course, the water temperature did not yet have time to warm up for swimming.