This is the 18th most frequent Hungarian word.
lehet
"Lehet" means "can," "may," or "it is possible" in English.
'Lehet' is used here to convey possibility or uncertainty about the event of rain.
Lehet, hogy ma esni fog.
It may rain today.
'Lehet' expresses the concept of possibility or the state of being possible here, asked as a question.
Hogy lehet ilyen gyorsan futni?
How is it possible to run so fast?
'Lehet' again signifies uncertainty or likelihood, in this case regarding postponing the meeting.