The best time to go to Krapets for ideal beach weather and outdoor activities is between June and September.
During these months, you'll experience warm, sunny days, great for relaxing on the Krapets Beach or exploring the nearby Durankulak Lake. The sea temperatures are also very pleasant for swimming, usually ranging from 22°C to 26°C. While July and August are the warmest and sunniest, June and September offer a slightly quieter experience with pleasant weather.
For those interested in birdwatching and nature, particularly around Durankulak Lake, the spring (April-May) and autumn (October) months are also excellent. The weather is milder, and you'll have the chance to observe migratory birds without the peak summer crowds.