Leonard Snart does not possess any known superhuman powers/capabilities.
As Captain Cold, Snart's nervous system has, over the years, developed reflexes that enable him to compenstate for the Flash's speed enough to sometimes stun the Flash with his cold guns. In addition, Leonard Snart is a very skilled marksman, though not on the same level as people like Deadshot and Deathstroke. He also has a very tactical mind, and his own personal sense of honor. He is a natural leader.
Captain Cold has demonstrated strength enough to lift over his head and throw another fully grown human male (Chillblaine). This would indicate that Cold possesses at least the strength of a man of his age, height, and build who engages in moderate regular weight bearing exercise.
Captain Cold possesses all of the same weaknesses as any other adult non-metahuman male.
Snow goggles - Minimize the flashes of energy given off by his guns within his field of vision. Snow parka.
Cold-guns - Which can create ice slicks, shatter metal or entomb victims in suspended animation in blocks of ice.