Visitors should prepare for a trip by bringing clothing for different types of weather
The entire second paragraph discusses how the different oceans/seas surrounding the park causes different weather. There can be dry air, blizzards, etc. which all cause a person to dress differently.
The fog is doing the same thing as a cat.
Bob Ewell was killed by Boo Radley, who stuck a kitchen knife into his chest on the night of Halloween. Bob wanted to get revenge on Atticus for trying to kill the children who were walking back from a Halloween school party.
