I found an excellent printable weather unit study @ The Teacher's Guide. The study was complete including vocabulary, a very simple introduction to formula calculation (4th grade), explanation of Celsius and Fahrenheit conversion, a review of the boiling point of water, an introduction to the root words of clouds in Latin, a poetry lesson and a comprehensive study of clouds. Although the lesson plans sound advanced they were quite simple to understand by my 8 year old and my 5 year old learned quite a bit about the water cycle and different types of clouds.
We began the week reading about clouds in an Abeka 3rd Grade Science book. My son is in Kindergarten/1st grade and my daughter is in 4th/5th; since we are a one room school, I sometimes give basic lessons from the 3rd grade manual to keep every one's attention. I have also found that if I give my son coloring pages to work on during the lesson he is a better listener. I used coloring pages on the water cycle @ Kid Zone. On day one we also wrote poems about clouds per the lesson plans.
In regards to sustainability, we have been working on another project @ Considering frugal. We have been previewing several grocery stores to see what kind of organic merchandise is available. After a discussion about sustainability, we set out to the local supermarket, I gave my daughter a clipboard with a chart of the foods we stock most often and asked her to locate organic versions and mark the price. I am proud to say that by the end of the week both children could identify organic labels and had a better understanding of how factory produced foods effect the sustainable food supply. If you are interested in what we found, you can read the full report @ Considering frugal.
Some variations I came across were themed cupcakes and play doe spaghetti and meatballs.