The regions used for weekly reporting were formally the East, West and Producing regions. In October 2015, EIA increased the number of regions and changed their names to better align the storage locations with the markets they serve and to provide more information to market observers and participants. The regions now are:
- the Pacific Region,
- the Mountain Region,
- the South Central Region,
- the Midwest Region, and
- the East Region.
The Pacific Region includes the following states: California, Oregon, and Washington.
The Mountain Region includes the following states: Arizona, Colorado, Idaho, Montana, Nebraska, Nevada, New Mexico, North Dakota, South Dakota, Wyoming, and Utah.
The South Central Region includes the following states: Alabama, Arkansas, Kansas, Louisiana, Mississippi, Oklahoma, and Texas.
The Midwest Region includes the following states: Illinois, Indiana, Iowa, Kentucky, Michigan, Minnesota, Missouri, Tennessee, and Wisconsin.
The East Region includes the following states: Connecticut, Delaware, District of Columbia, Florida, Georgia, Massachusetts, Maryland, Maine, North Carolina, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, South Carolina, Vermont, Virginia, and West Virginia.