Against a backdrop of mostly mild weather across the Lower 48, winter unleashed its fury on the West Coast a bit early this season. The frigid temperatures and unusually heavy precipitation have fueled natural gas demand at a time when storage inventories are low, a drought has reduced hydro-electric power supplies and regional utilities are having trouble receiving coal deliveries.

The result: historically high natural gas prices that have surged to levels not seen since the summer of 2018. The surge in prices has spread across the Pacific Northwest, farther south throughout California and inland across the Rockies.

On Thursday, Northern California’s PG&E Citygate recorded spot natural gas prices as high as $36.00/MMBtu. SoCal Citygate cash reached a $33.00 high, while Malin...