Drizzle — Kathleen Van Cleve

Eleven-year-old Polly Peabody needs to make it start raining. For her entire life, it has rained at exactly one o'clock every Monday afternoon on her family's magical rhubarb farm, until one Monday, when it stops. And then Polly's brother gets sick, really sick. Polly has to figure out how everything is connected and make it rain before her beloved Aunt Edith sells the farm. She has help from the farm itself, in the form of the plants and insects, including her best friend, Harry, a chocolate-tasting rhubarb plant. They all push Polly to confront her fears. But is it enough, and more importantly - is there enough time?