A Simple Investigation:
Scoop snow into a tall clear cylinder. A vase or mason jar work well. In my science lab, I used a graduated cylinder. Measure how much snow is in the container. (Many children have difficulty using a ruler.) Leave the container on your counter and check back periodically. Make careful observations. After the snow melts, measure how much water is in the container. Analyze your results. What are your conclusions? Introduce a variable, and place identical jars in different spots, like a sunny window. Would you have the same results with different types of snow?
To extend this investigation, leave the jar on the counter and observe how quickly the water evaporates.