Summarized List: Weather
Rain reduces visibility, decreases temperatures, and causes some metals to rust.
In rainy weather, visibility is reduced to a maximum of 50 feet in any direction. You take a -3 penalty to Perception checks using your sight or hearing.
Rain causes creatures to experience the effects of one temperature level cooler than normal (Cold 1 if the area normally has no extreme temperature.)
If the area is already Cold 2 or 3 in dry conditions, rain is replaced by snow.
Any equipment containing Iron, Bronze, Steel, or Carbon Steel will rust if used or left outdoors in the rain.
Every 30 minutes, if an item made of one of these materials has been exposed to rain, make a durability check for it and reduce its condition by one level on a failure, unless the item's condition is already 2 or lower.
Whenever this effect reduces the condition of a weapon or item to less than 3, that item's material may change.