The boiling point of hydrogen halides varies in the order

There is a presence of the dipole-dipole interactions i.e. hydrogen bonding in the hydrogen halides which is mainly responsible for the determining the order of boiling point, and the correct order will be 

$\mathrm{HF}>\mathrm{HI}>\mathrm{HBr}>\mathrm{HCl}$

Here, the higher boiling point of hydrogen fluoride is due to the presence of strong hydrogen bonding between $\mathrm{HF}$ molecules which leads to the association of $\mathrm{HF}$ molecules and requires higher energy for boiling so it have higher melting point.