FCAW is considered a low-hydrogen process, so if the plate material is ASTM A131 EH 36, it will fall into category B(notice the welding processes listed. ASTM A36 is in category A and B, but the welding process used determines whether it falls into A or B. Typically low-hydrogen electrodes require less preheat in the material than non-lowhydrogen electrodes.
Don't forget to look at the subscripts, 1/8"-3/4" has an "a" by the temperature(so Note "a" applies)
"Note a: When the base metal temperature is below 32°F[0°C], the base metal shall be preheated to a minimum of 70°F[20°C] and the minimum interpass temperature shall be maintained during welding."