| HumbleGamer |
It lasts the whole turn.
If it had given the bonus only for the triggering attack it would had said that, like the rogue nimble dodge reaction.
Quote:
PFS Legal Nimble Dodge ReactionFeat 1
Rogue
Source Core Rulebook pg. 183
Requirements You are not encumbered.
Trigger A creature targets you with an attack and you can see the attacker.
You deftly dodge out of the way, gaining a +2 circumstance bonus to AC against the triggering attack.