As the rate of combustion increases, the degree of superheat increases throughout the entire firing range.

With a constant firing rate and steam consumption equal to generation, a decrease in the incoming feed water temperature results in a superheat temperature decrease.

With large amounts of excess air, superheater outlet temperature will decrease due to the lack of sufficient time for heat transfer to take place.

Carrying boiler water total dissolved solids higher than normal could result in a decrease in the degree of superheat.