BACKGROUND Student heavy drinking and associated problems are common at most universities and fluctuate throughout the calendar year, with marked increases during celebrations. Most studies of student drinking are limited to the academic year itself, and relatively few focus specifically on special heavy drinking events. Even fewer studies include drinking during summer break and subsequent school return. METHODS In the context of an experimental protocol, beginning in January 2014, alcohol-related characteristics were evaluated 8 times over 55 weeks for 462 college freshmen, including periods that incorporated a campus festival, summer, and school return. Baseline predictors of drinking quantities over time included demography, substance use patterns, as well as environmental and attitudinal characteristics. Product-moment correlations evaluated relationships between baseline characteristics and subsequent quantities, and simultaneous entry regression analyses evaluated which characteristics most robustly predicted usual and maximum drinks over time. RESULTS Maximum drinks per occasion increased 18% from the early spring (4/8/14 to 5/6/14) to the campus festival period (5/7/14 to 6/3/14), decreased 29% in the summer (7/8/14 to 8/5/14), and increased 31% on school return (10/7/14 to 11/4/14). The most robust predictors of higher quantities in regression analyses included items from each of the 3 major domains with the most consistent results seen for most baseline alcohol-related items and descriptive drinking norms (R(2) = 0.20 to 0.31). CONCLUSIONS These data demonstrate important changes in students' drinking during the calendar year, including expected large increases during the month of a 1-day festival, large decreases over the summer, and resumption of relatively high quantities upon return to school.