Liquefied cryogenic gases are approximately at their boiling points.

Note: The boiling point of N₂ is just a shade lower than O₂ bp.  Therefore a LN2 trap can  condense oxygen from the air over time.  Very unhappy situation. 

Note that liquefied ammonia does not officially qualify as a "cryogen" byt he definition given previously.  Still, the same safety principles are entirely relevant.  (And ammonia has other hazards as well.)