Varna is located in the Mediterranean climate region, and as such tends to have warm to hot summers and cold, and usually dry winters. During the hot summer days you can enjoy the many sandy beaches in the area or escape to the picturesque and considerably cooler (Balkan) Mountains. Thunderstorms can brew up quite quickly and regularly during the summer months so be prepared as flash flooding and hailstorms are not uncommon.
Remember to carry sunscreen with you during the hot months and a warm scarf and hat during the autumn and winter.