Do missiles need anti-icing?
In a history of NASA's Icing Research Tunnel, &quot;We Freeze to Please,&quot; NASA SP-2002-4226, Fig. 5-2 shows Hellfire missiles being tested.  But it conspicuously mentions nothing about de-icing systems for them, unlike the many pages that it devotes to de-icing for other aircraft and aircraft parts.  So it's likely that such de-icers are either still classified, or were deemed unnecessary.
Dohn Joe's remark, that Hellfires this icy could not be laser-guided, suggests that classified is more likely.