When can I stop or call a game for weather, conditions or an injury?

Starting the game: the home coach decides whether the grounds and other conditions are suitable for starting the game (4-1-1).

Calling the game (4-2-7, 10-2-3): the umpire may call (end) a game for weather, or if playing conditions in or around the facility become unacceptable for continuing safely.

Lightning (NFHS guidelines): suspend play as soon as thunder is heard or lightning is seen, and send everyone to a safer place: a substantial building with plumbing and wiring, or a fully enclosed metal car or bus. Wait at least 30 minutes after the last thunder or lightning before resuming; any new thunder or lightning restarts the count.

Possible concussion: a player showing signs, symptoms or behaviors consistent with a concussion must be removed immediately and can't return until cleared by an appropriate health care professional. You don't diagnose: remove the player and tell the coach.