There is no rhyme or reason as to when thieves will strike.
There is.
It's literally AP's job to track trends and theft patterns, including seasonal trends, new releases, etc.
We know to catch certain people because they shoplift enough for us to determine their routines or behaviors/M.O.
It might seem random to an outside observer, but as an example, we know that infant formula is a summer trend; it just doesn't get taken as often during winter months. We track organized groups, so we're aware of what stores they're hitting; a particular group might not cross a bridge to hit stores on one half of a city, for example -- almost like they have a territory in which they'll operate. All of this kind of stuff can be tracked, analyzed, and used to more-or-less accurately predict theft. We use it to plan our protection strategies and responses.
So yeah, while we can't point and say
I DEFINITELY KNOW THAT SOMEONE WILL STEAL THIS ITEM HERE TODAY, we still have a pretty good idea of what to look out for, and often when to watch specific areas or items.
Also, theft will drop when there's crappy or rainy weather. Cuz nobody likes to go out in crappy weather. It can be as simple as that.