In this activity, learners will simulate the processes of the water cycle at home in a plastic sandwich bag. Learners will decorate their bag to model a water basin, fill their bag with colored water, and hang their bag of water on a window. Over time, learners will notice their water turn to vapor, condense back into liquid, and precipitate back into the water basin at the bottom of the bag. This activity includes step-by-step instructions with pictures and a "what's the science" section to explain the scientific processes that are occurring. There are suggestions for turning this activity into an experiment at the end of the guide.