Admissions volume is not evenly spread through the year. January, the weeks after the holidays, and the first warm weeks of spring bring the highest call volume — the holidays make the pattern visible to families, and January makes it visible to the person drinking.
Summer creates the opposite problem: barbecues, shore weekends and golf outings make drinking invisible again, which is why we do not treat a quiet July as progress.
If you know a particular season is your hardest, plan for it. Starting IOP in November rather than January is one of the more effective things a person can do for themselves.