It's the first day of Spring, and at the London home of Roger and Dorothy Hilton, everyone, including their three children, Catherine, Ann and Martin, is suffering from spring fever. Oldest daughter Catherine is languishing over artist Paul Francis, who makes sure his wife Ethel is always present when he paints Catherine's portrait. Martin, meanwhile, longs to travel around the Continent until he meets Joan Collett, the pretty girl next door. Ann is enamoured with the works of nineteenth century romantic painter Dante Gabriel Rossetti. Roger is preparing the taxes of stunning actress Beatrice Gwynn and under the influence of the glorious day, allows her to persuade him that they can only finish the work that night at her apartment. Even the domesticated Dorothy draws the attentions of Frank Haines, whose sister, Muriel West, is Dorothy's best friend. When Frank insists on visiting the Hiltons at dinner that night to find out if Dorothy is really happily married, she tries to gather her family around her, only to discover that everyone has other plans for that evening. She manages to discourage Frank, but when Roger returns with a huge bunch of flowers for her, the oddity of that act convinces her that he really was having an affair with Beatrice. Dorothy responds by telling him of Frank's offer of marriage. Catherine returns home distraught because Paul did not keep his date with her, and in fact, he and his wife are leaving for Majorca. At first it seems as if spring fever will destroy the family, but very soon everything has been resolved and they settle down happily for the night.