Madre Fire
The Madre Fire was a large wildfire that burned in San Luis Obispo County, California. The fire was the largest of the 2025 California wildfire season, having burned as of July 26, until being surpassed by the Gifford Fire two weeks later.
Background
A persistent Red flag warning, issued by the National Weather Service, was in effect across the region during the onset of the Madre Fire, reflecting a convergence of triple-digit temperatures, single-digit relative humidity, and strong downslope gusts. These conditions heightened the likelihood of rapid ignition and extreme fire behavior.Initial spread was expedited by cured grasslands, dense chaparral, and steep terrain along Highway 166, which funneled wind through canyons. The blaze grew from just a few hundred acres at ignition to by the evening of July 2, and surged to more than by the following morning.
Persistent drought across Southern California compounded the threat. According to Cal Fire’s statewide archive, rainfall totals since the previous winter amounted to less than 70 percent of average, leaving both live and dead fuel moisture at critically low levels. This long-term drying accelerated flammability, while weakened marine layers allowed hot, dry air to dominate inland valleys and foothills.
Overall, the alignment of extreme weather, record-dry fuels, and complex topography provided the backdrop for the Madre Fire’s explosive growth. Within its first 48 hours, it became the largest wildfire of the year in California, ultimately burning before full containment on July 26.
Progression
The fire began at 1:07 p.m. on July 2. The cause is currently under investigation. It quickly grew in size to, before reaching over. Late on July 2 the fire reached, before exploding in size to acres early on July 3. Later on July 3 the fire reached acres in size. The fire was fully contained on July 26th after burning acres and injuring 2 firefighters.Effects
The fire prompted the closure of California State Route 166. Evacuation orders were issued by the California Department of Forestry and Fire Protection on July 2 and 3 for zones SLC-337, LPF-017, SLC-226, SLC-264, SLC-265, SLC-299, SLC-312, SLC-338, and evacuation warnings for zones SLC-312, SLC-263, SLC-298, SLC-300, SLC-313, SLC-339, and SLC-358. 50 structures have been threatened by the fire.The fire is the second largest of the 2025 California wildfire season.