Updated: 8:29 a.m. July 20

First discovered: 31 hours ago, 1:26 a.m. July 19

Initial location: San Ardo Rd and Glau Canyon Rd, East of Lockwood, Monterey County, Calif.

Fire unit: Cal Fire San Benito-Monterey Unit

Fire type: Wildfire

Fire name: Williams Fire

Williams Fire initially started 1:26 a.m. July 19 at San Ardo Rd and Glau Canyon Rd, East of Lockwood in Monterey County, California.

As of Monday morning, it had swept through 120.9 acres. By Monday morning, the fire crew effectively contained 20% of the fire. Currently, there are no details on the cause of the fire.

Fire containment

What does it mean for a fire to be 20% contained?

The percentage indicates how much of the fire perimeter has been surrounded by a control line. In this case, it means that 20% of the wildfire is halted from spreading, while 80% is still uncontrolled.

Containment is part of a larger plan for managing a wildfire. It is normally expressed as a percentage and it refers to how much of the fire perimeter has been surrounded/enclosed by a control line that firefighters create. The containment percentage indicates a certain level of control, but it doesn’t always correlate to safety level. Also, it’s important to note that containment doesn’t mean a fire is out.

How is containment measured?

The incident’s central command constantly receives progress reports from firefighters on the ground. As the fireline is constructed, inspected or reinforced, mappers record those details to adjust the containment percentage. The percentage tells the public how much of the fire perimeter is believed to not go beyond the control lines.

Source: Cal Fire