Irish flights could be affected by the extreme weather affecting parts of the US.
Temperatures have plunged to -29 degrees in some places, with up to 21 deaths so far.
Winter Storm Grayson has led to a state of emergency being declared up most of the east coast.
As a result, a number of flights from the US to Ireland were cancelled yesterday, and there could be further disruption today.
In addition, travel agents are expecting their busiest day of 2018 as thousands of people book trips after returning to work following the festive period.
Greece and Cyprus are among the most popular destinations this year.