What is the purpose of the couple arriving at Manderley in the spring?

The setting itself is what makes their arrival in the spring so significant. Although the narrator's new home is filled with the memories of a dead wife, the grounds and their beauty allow her to fall in love with her new home. A walk with her husband unveils the beauty of the estate; the valley of azaleas, the cove, a game of fetch with her husbands dog. All of these warm her to a home that is filled with cold and dread. We can see a sense of hope from this vision of the estate that wouldn't have been possible in another season.