Wildfires are complex phenomena that have served a vital role in ecosystem function for millennia. However, thermal alterations to dissolved organic matter's (DOM) solubility and chemical features can change disinfection byproduct (DBP) formation dynamics. Physicochemical changes to DOM are influenced by several factors, the most prominent being heating temperature. In this study, mineral soil samples were collected from fire‐prone areas, artificially heated in a muffle furnace to simulate wildfire heating, and leached. As heating temperature increased, chloroform and dichloroacetic acid yields decreased and increased, respectively. Of particular interest was the stimulation of dichloroacetonitrile, a highly toxic and unregulated DBP, at moderate heating temperatures. To demonstrate further insight into the chemical attributes of wildfire‐impacted DOM, optical properties were used as proxy measurements. This work provides water utilities with information on how wildfires can alter DBP formation potential, and a means to investigate correlations between intrinsic optical measurements and DBP yields.