The mood at the beginning of the story is a pleasant one, but generally matter of fact. The story begins on a sunny day, and the opening paragraph describes the people.
The first sentence of the story sets the tone. It tells us the specific setting, including the date and time of day and how many people are in the village.
The morning of June 27th was clear and sunny, with the fresh warmth of a full-summer day; the flowers were blossoming profusely and the grass was richly green.
This paragraph makes us think that the story is going to be pleasant. Word like “clear and sunny” and “full-summer” give us warm and fuzzy feelings. Most people associate summer with warmth and happiness. Summer is a peaceful time. The description of the green grass and blossoming flowers also makes us happy, and makes us think the story will be pleasant.