Do weather effects stack?

[ziltmilt]

Wind & rain can have overlapping effects. Do they stack?

For example: rain has the same effect on PER checks as severe wind (-4). If you also had severe wind during a rain, would PER checks then be -8?

Seems pretty high to me, but not unreasonable.

[Howie23]

I would think they would stack. -8 might be somewhat high, but perception seems more difficult to me in driving rain than either wind or rain alone. From a rules basis, I'm not sure....I would feel very comfortable stacking them, though.

[The Elusive Jackalope]

It would seem to me that they stack. Severe wind and rain together are essentially a storm according to the PRD (sans lightning), and a storm does imposes a -8 penalty to Perception if I'm not mistaken (in addition to making normal ranged weapon attacks impossible).