The Largest Wildfire in California History Burned 1 Million Acres

The August Complex Fire holds the record as the largest wildfire ever in California, burning over 1,032,648 acres (417,898 hectares).

This multiple-wildfires event was ignited by lightning in August 2020 and quickly spread across seven counties. Cal Fire struggled to contain the massive blaze, which impacted Mendocino, Humboldt, Trinity, Tehama, Glenn, Lake and Colusa counties [source: Cal Fire].

The Dixie Fire, one of the most infamous California wildfires, burned 963,309 acres (389,837 hectares) across Butte, Plumas, Lassen, Tehama and Shasta counties. Sparked by power lines, the fire destroyed the historic town of Greenville and became one of the most destructive wildfires in state history.

Like many of the largest wildfires, the enormous volume of heat and smoke altered local atmospheric conditions, leading to the formation of huge pyrocumulonimbus clouds that towered over the landscape.

The Mendocino Complex Fire consisted of two major blazes — the Ranch Fire and the River Fire — which together scorched 459,123 acres (185,800 hectares). The Ranch Fire alone burned over 410,000 acres, making it the largest single (non-complex) wildfire in state history, until that distinction was surpassed a few years later by the Dixie Fire.

The 2018 Ranch Fire was also surpassed (in terms of single-ignition fires) by the 2024 Park Fire. The Mendocino Complex Fire raged from July 27 to September 18 [source: Cal Fire].

The Park Fire was believed to have been started by an act of arson. It burned 429,603 acres (173,854 hectares) over the course of two months before being suppressed.

Coming at the end of July 2024, the hottest month ever recorded in California, the fire's size and speed were fueled by the heat and the recent extremely dry conditions.

This fire burned 396,625 acres (160,508 hectares) across multiple counties, making it one of the largest wildfires in Cal Fire's list of significant events. It was caused by a severe lightning storm, igniting dozens of smaller fires that eventually merged into a massive inferno.

Burning 379,895 acres (153,738 hectares) in the Sierra National Forest, the Creek Fire became the second-largest single, non-complex fire in state history.

The fire destroyed hundreds of homes and forced massive evacuations, with Cal Fire battling extreme fire conditions.

Burning 363,220 acres (146,990 hectares) across Napa, Sonoma, Lake, Yolo, Solano and Colusa counties, the LNU Lightning Complex Fire was part of a series of multiple wildfires sparked by a rare summer lightning storm.

At least one of the fires is believed to have been started by arson. It destroyed nearly 1,500 structures and forced thousands to evacuate.

The North Complex Fire, ignited by lightning, burned 318,935 acres (129,068 hectares) and devastated parts of Butte, Plumas and Yuba counties. It was one of the deadliest wildfires in California history, claiming at least 15 lives and destroying nearly 2,500 structures.

The Thomas Fire burned 281,893 acres (114,078 hectares) across Ventura and Santa Barbara counties. Strong Santa Ana winds fueled its rapid spread, making it one of the most devastating wildfires in California history at the time.

One of the most infamous Los Angeles fires, the Cedar Fire burned 273,246 acres (110,579 hectares) and was ignited by a lost hunter setting a signal fire. It destroyed over 2,800 structures and resulted in 15 deaths, making it one of California's most destructive wildfires.

The Rush Fire burned approximately 271,911 acres (110,038 hectares) in Lassen County. Unlike other California wildfires, it mainly affected remote areas and rangelands, limiting its structural damage.

The Rim Fire ignited in August in Tuolumne County and burned for nine weeks while firefighters worked to contain and suppress the flames. It consumed 257,314 acres (104,131 hectares) and was started when a hunter's fire got out of control.

While largely contained to the Sierra Nevada wilderness, there were still over 100 structures destroyed.

This list chronicles the top 12 destructive fires in the modern history of California, ranked by acres burned. Each entry provides insight into the magnitude and impact of these destructive wildfires, although there are other ways to measure the devastation and scope of a fire's damage.

Sometimes, the biggest fires aren't the most costly to human life and property. Out of the top 20 in terms of acres burned, the Camp Fire of 2018 was the deadliest in state history, leading to 85 deaths. Other fires, such as the Nuns Fire (2017) and the Palisades Fire (2025) caused thousands of structures to burn.

We created this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.