Lapseki: are you wondering about the weather you might find during your holiday? Befor organizing a holiday we always think about the wheather we might find when we get there. In Lapseki the average yearly temperature is 18°C. During the hottest month, which in this case is July, the temperature can get up to 30°C and the temperature of the sea reaches 25°C. Instead the coldest month is January, reaching a minimum temperature of 8°C. Here instead the water temperature drops to 11°C.