On a Summer's Day
Crits and Threats
A natural 20 on any attack roll is always a confirmed threat, regardless of the threat range of the weapon used. It is also a guaranteed hit. Damage dealt on a natural 20 attack roll follow the normal Pathfinder rules.
Threats whose roll was less than 20 (for example, a weapon that has a threat range of 19-20) must be confirmed by normal Pathfinder rules.