In the early morning hours of Saturday, August 1, after a brief lull in fire activity due to low overnight temperatures, the Apple Fire began to further display aggressive and rapid activity due to the rising temperatures, low humidity and strong winds as well as rugged inaccessible terrain that the fire proceeded to advance towards. This caused the fire to explode into the Banning Bluff area which spurred additional mandatory evacuations as it rapidly burned further into the San Bernardino National Forest and up along the south facing side of the San Gorgonio Mountain Range. By 12 pm, the fire had been reportedly sized up at 4,100 acres with still zero percent containment. Additionally, up to 7,800 people had been ordered to evacuate. Within less than 24 hours, the fire had rapidly expanded by 13,000 acres to encompass upwards of 15,000 acres (6,070 ha) by near midnight as the fireline still remained zero percent contained. By Sunday night, on August 2, it surpassed 20,500 acres (8,296 ha) while firefighters finally reached 5% containment. The San Gorgonio Wilderness was also closed off by an Emergency Forest Closure Order, prohibiting entrance to any part of the wilderness.