Happy New Year! For many of us, 2014 is starting out with a headache and the need for a large glass of water, since we sent 2013 out with a bang.

To get an idea of where the hardest partying last night went on, and where the most bleary-eyed breakfasts are taking place today, we ranked the states using the BI Hangover Index. The darker the state, the more revelry and its aftermath. Read more about our methodology below.

The BI Hangover Index is made up of four components:

Binge Drinking: This measures the percentage of adult respondents to the CDC's 2010 Behavioral Risk Factor Surveillance System survey who answered yes to a question on binge drinking (defined as men having five or more drinks on one occasion, and women having four or more drinks on one occasion).

Bars per 100,000 residents: The number of bars in each state was found in the Census Bureau's 2011 County Business Patterns (NAICS code 722410), and this number was divided by the most recent Census estimates of each state's population from the American Community Survey.

Beer, Wine, and Liquor Stores per 100,000 residents: Similarly to bars, the number of Beer, Wine, and Liquor Stores in each state was found in the Census Bureau's 2011 County Business Patterns (NAICS code 445310), and this number was divided by the most recent Census estimates of each state's population from the American Community Survey.

Breweries per 100,000 residents: The number of breweries per capita in each state was taken from the Brewers Association's capita per brewery 2012 report.

The 50 states and Washington, D.C. were percentile ranked in each of these four categories, and the BI Hangover Index for each state is the average of the four rankings, giving a score with a theoretical range between 0 and 99 for each state. The map (generated using QGIS) compares the Hangover Index scores for the states, with a darker blue indicating a higher score.

Here is a breakdown of each state's score: