By definition, situational irony is when something happens that was the opposite of what was expected. In this example, a man goes on a picnic in the Mojave Desert, but it gets ruined by rain. Since this is in a desert, you wouldn’t expect it to rain, you would expect it to be dry. Since it happened anyways, this is situational irony.
Faith seems quite lonesome and sad, wishing for her loved husband to stay with her. And Goodman Brown seems very devoted to wherever he is going, and assures his wife she doesn't need to doubt him for he would be back soon. I hope this helps!
