This two-in-one book features the highs and lows of a pair of meteorological opposites. A boy, his father and five diverse apartment residents experience a heat wave in one half of the story and, with a flip of the book, seemingly endless rainy days in the other. Comparisons between the two weather extremes play out in Greenseid's (When Aunt Lena Did the Rhumba) full-spread acrylics and lively spot illustrations, which depict the city-dwellers going about their daily routines. Initially, all are content with a climate change, as when it finally rains after a bout of scorching summer heat. "Jerome Katz read a book about dinosaurs.... Jon Griswold danced as he cleaned his apartment." But when the downpour persists, "People began to get grouchy. Jerome Katz got soaking wet when he left 3-G to return the book about dinosaurs to the library.... Jon Griswold sneezed and coughed." Descriptive to a fault, Dragonwagon's (Bat in the Dining Room) narrative may not offer enough of a story for young readers, even with the flip-over format (perhaps of greater interest to adults, one character reminisces about a trip to Turkey, another quotes Bible verses). But Greenseid's illustrations buffer the more drawn-out passages, entertaining readers with her diverse perspectives, cheery hues and comfy, rounded edges. Ages 4-8. (May)