Dozens of flights have been cancelled and ferry services disrupted as freezing and snow conditions struck the Greece, Italy and Turkey.
Turkish low-cost carrier Pegasus Airlines was forced to ground a raft of flights to and from Istanbul Sabiha Gokcen airport on Saturday, blaming adverse weather conditions.
Airports in Sicily, Bari and Brindisi closed on Saturday while Rome saw freezing temperatures.
More than 20 people are reported to have died across Europe as temperatures fell to as low as minus 15C in northern Greece.
Temperatures in Athens failed to rise above zero and several islands were covered in snow over the weekend.
At least 10 people died of cold in Poland. Night temperatures in Russia plunged to minus 30C and Prague experienced its coldest night so far this winter.
Cold and wintery weather is forecast to hit the UK later this week.