OLYMPIA—Governor Jay Inslee declared a statewide state of emergency on Tuesday relating to the growing risk of wildfires, including a statewide prohibition on most outdoor and agricultural burning through September 30.

“Washington is facing a historic drought, and we have already experienced record-breaking heat. We must be vigilant in our efforts to prevent wildfires and the loss of life and destruction of land and property that comes with them,” Inslee said. “We don’t want a repeat of recent years with dangerous wildfires across the state that have destroyed towns, killed livest...