Teaching Elementary aged students certain ideas can be difficult. Children are extremely hands on when it comes to learning, and it can often be nearly impossible to teach them abstract ideas.
Which is doing projects related to the weather can be so effective.
Weather is all around them, and it is something they can literally feel. Using these weather projects will not only help them to better understand what weather is and how it works, but will allow you to teach them about art, math, and history without them even knowing.
You know exactly what a 5 day forecast looks like. It hasn't changed much over time, and we constantly rely on it to plan ahead (even though it often ends up being wrong!)
Children, however, do not watch the news the way we do. Here is the project:
Make up sheets of paper that have 5 separate columns side by side, with the days Monday through Friday listed one by one across the top, so that each column corresponds with a day. Instead of looking forward to what will happen, however, have your students go outside or look out the window each day and color what the conditions are like. Sunny, cloudy, rainy, snowy or whatever. Also, get a digital thermometer that records the outside temperature. Have them look at the thermometer and include the temperature underneath their drawing of the conditions.
This is a simple, fun project that will help teach your students to pay attention to the world around them. An added benefit, is that when they see the 5 day forecast on the news the next week with their parents, they will have something to talk about with them, and will pay attention to the news a little more closely.
HOW MUCH DID IT RAIN?:
During or soon after a rainy day, ask your kids: "How much did it rain?"
They will, as kids do, come up with some really fun answers. Then ask them if they can think of a way to measure the rain. Let them brainstorm here and shoot out ideas. Then, pick the best 2-3 (one of which will be a device similar to the ones used to actually measure rainfall) and put them to the test. This project gives your students a chance to be creative, and it really applies to science as you will be analyzing your results. A good introduction to scientific process and problem solving.
YOU CAN"T SEE IT, BUT YOU KNOW IT IS THERE
You can feel the wind, but you can't see the wind. I would recommend this project for grades 3 and up, just because if you go too much younger you may have more than you can handle. First, you need a set number of kites (which I know brings money and what not into the issue, go here: http://www.aloha.net/~bigwind/20kidskites.html for a fun and cheap way to make your own). One kite to ever 1-3 kids works best. Then, pick a windy day, and a day that is not windy (Or, you can do it all in one day and hope you get some gusts AND some stillness). Have your students record how the kites work with a lot of wind vs. little wind. Ask them why this is. Ask them why running might help the kite fly.
The answers to these questions are somewhat complex, which is okay! You do not need to answer them. This isn't about your students understanding the principles of wind resistance etc. It is about putting the idea in their heads that there is something more than meets the eye. They may not, at the time, understand why kites work better with wind than without it, but they will know that they do. This little seed of knowledge will, in time, grow.