Melting and boiling points of benzene and fluorobenzene This species is a derivative of benzene, with a single fluorine atom
  attached. Its melting point is -44 °C, which is lower than that of
  benzene, indicative of the remarkable effect of fluorination on the
  intermolecular interactions as seen throughout organofluorine
  chemistry. In contrast, the boiling points of PhF and benzene differ
  by only 4 °C.


Why is this true? Wikipedia doesn't elaborate on why. 

From what I understand the melting point is the point at which the solid and liquid forms are in equilibrium. 

Boiling point is the point at which the liquid and gas phases are in equilibrium. 

I know that intermolecular forces play an integral role in melting and boiling point. However, why does it seem that the strength of the intermolecular forces in the solid phase is stronger than that in the liquid phase for fluorobenzene?
The answer really doesn't have much to do with fluorine.  Beacall's 1928 The melting-points of benzene derivatives explains on the first page that it has long been known "that the more symmetrical the constitution of a benzene derivative, the greater the resistance it offers to the passage from the solid to the liquid state".  

In the more modern Effect of molecular symmetry on melting temperature and solubility:


  As a general rule, symmetrical molecules in crystalline form have higher melting temperatures and exhibit lower solubilities compared with molecules of similar structure but with lower symmetry. Symmetry in a molecule imparts a positive amount of residual entropy in the solid phase (i.e., more possible arrangements leading to the same structure). This means that the entropy of a crystal of symmetric molecules is greater than the entropy of crystal of a similar, but non-symmetric molecule. 


Benzene and hexafluorbenzene have almost the same melting point, while monofluoro, monochloro, monobromo benzene all have much lower melting points.   

Both benzene and hexafluoro-benezne have a very stable "herringbone" crystal structure, where the edge of one ring approaches the center of another ring in a perpendicular manner.  



So realizing that the cyrstal structure of benzene is unusually stablized, it is understandable that the melting point of benzene is higher than monofluorobenzene, but the boiling point is not.