Waffle House is known for being the place you can depend on to be open 24 hours a day, 365 days a year if you need to grab some grub.

The restaurant chain, founded in Georgia in 1955, does, however, close on very rare occasions — most notably extremely inclement weather.

That instance is infamously known as the Waffle House Index, a surprising metric used by the government to gauge the severity of a storm and determine the resources needed to aid recovery.

According to Waffle House, the unofficial metric was coined by Craig Fugate, the Director of the Federal Emergency Management Agency, in 2011, after a tornado devastated Joplin, Mo.

“If you get there and the Waffle House is closed? That’s really bad. That’s where you go to work,” he joked at the time.

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Fugate’s flippant remark was turned into the Waffle House Index: a color-coded scale used to reference during disaster recovery.

The scale is as follows:

• Green: The restaurant is serving a full menu, indicating the restaurant has power and damage is limited.
• Yellow: The restaurant is serving a limited menu, indicating there may be no power or only power from a generator or food supplies may be low.
• Red: The restaurant is closed, indicating severe damage.

The breakfast chain has embraced the term, and has even created a “hurricane playbook” to help their locations reopen quickly to help feed those in need.

As Hurricane Milton impacts Florida, Waffle House has launched a map of their locations affected by the hurricane’s path.

The restaurant plans to try to update customers on its operation capacity amid Hurricane Milton.