Usually, it will be warmn enough in Shanghai in May. Sometimes, the temperature during daytime has reached 25C. However, the weather is also changeful in May while the rainfall visits Shanghai in late May. The temperature difference between day and night is great, too.

A T-shirt or thin knitted sweater is enough for adult. In case of the cool rain, please prepare thin sweater and wind-proof jacket for the kids. Anyway, you'd better pay attention to the weather forecast before leaving.