There are three types of Napalm bombs: NP1 (most commom napalm used in Vietnam), NP2 (super-napalm) and NP3.  

napalm bomb

The difference between each of the three bombs is that they burn at different temperatures.  In combustion, NP1 develops a temperature ranging from 900-1,300°C and burns for approximately three to fifteen minutes. NP2 produces far greater heat: 1,500 - 2,000°C.

napalm bomb loaded onto plane

napalm strike in Vietnam