The call to cancel is typically made by the operating facility. We usually build one or more weeks of make up days in case of bad weather and cancellations.
We always communicate the final call a few hours before the games, day-of. But generally you can expect us to play through a light drizzle. Any lightning in the area and games are first delayed then cancelled.
If a league has multiple cancellations, all games may not be able to be rescheduled.