The weather is a great scientific topic to study with young kids, because the results are so tangible and relevant to their lives. Is the temperature too low? Maybe we should play inside instead of going to the park. Is there a chance of precipitation today? Better take a jacket and umbrella if we have somewhere to go. Even kids as young as preschool and kindergarten can learn to read a thermometer or make simple scientific apparatus such as a wind sock or rain gauge. Even if they don’t learn the difference between cirrus and cumulus, in today’s fast paced society, every child should spend at least some time cloud watching. This science project will teach you how to make a weather vane.
Wind Basics
This homemade weather vane science project is yet another easy way for kids to get hands-on experience being meteorologists. For added educational value, kids can easily make their own homemade compass to help orient their weather vane while simultaneously learning something about the Earth’s magnetic field.
Historically, weather vanes have been in existence and used to help predict the weather for over 2,000 years. Unfortunately, these predictions are not always very accurate. However, although meteorology is a lot more complicated than the direction the wind is coming from, knowing this information can be used to make better educated guesses about the weather.
For example, if the wind is coming from the north in the northern hemisphere, one might expect the temperature to cool off since average temperatures are typically colder the closer one gets to the Earth’s poles. (In the southern hemisphere, southern winds would be more likely to have a cooling effect.) Conversely, if the wind was coming from the direction of the equator (so the south in the northern hemisphere, north in southern hemisphere), one might predict warmer weather is on its way. If you live near an ocean, wind from that direction might suggest an increase in humidity (the amount of moisture in the air). Whether or not their predictions are reliable, kids can have fun practicing their weather forecasting skills.
How to Make a Weather Vane
Homemade Weather Instrument Supplies Needed:
- straw
- unsharpened, unused pencil
- empty circular plastic container with lid (such as sour cream, cottage cheese, yogurt, etc.)
- playdough (enough to fill the bottom of your container about 1/2 inch)
- ball pin
- 1 sheet of card stock
- needle
- refrigerator magnet (ours looks like a silver push pin in the picture above)
- small square piece of Styrofoam (at least about 1″ x 1″)
- bowl
- glue
- scissors
- x-acto knife
- pencil
- markers
- tape (optional)
- ruler (optional)
Homemade Weather Vane
Let’s walk you through the simple steps for how to make a weather vane. First, trace the lid of the plastic container onto the cardstock and cut it out. Use the X-acto knife to make an “x”-shaped hole in the lid of the plastic container and use the hole to mark the center of your circle. If desired, draw a compass rose onto your cardstock circle. Otherwise, just label the 4 cardinal direction with N, S, E, and W. Glue the circle onto the lid.
If desired, cut out and decorate a piece of cardstock to wrap around your plastic container. Ours says, “Which Way Does the Wind Blow?” and I had my kids decorate it with a weather theme (storm clouds, sun, rain, lightening, etc.)
Attach the label to the plastic container with tape or glue. Fill the inside of the container with about 1/2 inch of play dough. After the glue dries on the lid, use the X-acto knife to cut an “x” in the center of the paper and push the unused pencil through the lid.
Finishing up your Homemade Weather Vane
Place the lid back on the container, pushing the pencil into the playdough so that the pencil is firmly held in place sticking straight out of the container.
Next, flatten your straw a bit, so that you can see a crease on the top and bottom. (If your straw has a bendy section, cut if off first.) Using the creases as a guide, cut a small slit on the top and bottom of each end (4 slits total). Each slit should be about 1/4 inch in length.
Cut out a square and triangle from the cardstock to make an arrow’s tail and point. Our square was 3″ on each side and our triangle had a 2 inch base and a 1.5 inch height. However, the exact dimensions (and even shape) are not really that important. What is important is that the tail of the arrow is much larger (has a greater surface area) than the point.
Decorate the tail and point if desired.
Place the square and triangle onto the ends of the straw. Add a little glue along each slit for added security.
Putting the top on the Weather Vane
Using the crease in the straw again as a guide, push a ball pin through the straw and into the pencil, doing your best to make everything as straight as possible. Since the square end of the straw is heavier than the triangle, placing the pin a little closer to that end will help it be better balanced and remain straight instead of tipped. Our pin is located about 1/3 of the length of the straw (about 2.5 inches) from the square end (2/3 of the length (about 5 inches) from the triangle end).
Now your weather vane is ready! Before you use it however, you’ll want to orient the directions properly so that you know which direction the wind is coming from. To do this, you could use your own compass. However it is more fun to make your own.
Homemade Compass
The first thing you need to do to make your homemade compass is to magnetize your needle by rubbing the magnet in the same direction from one end of the needle to the other for about a minute. (Do not rub it back and forth.)
Next, glue the magnetized needle onto the Styrofoam.
After the glue dries, place the Styrofoam and needle into a bowl of water and the needle will line up with the Earth’s magnetic field which runs between the North pole to the South pole. You can check the accuracy of your homemade compass with a real compass.
Using your Homemade Compass
Unfortunately, you will not know which end of your needle is north and which is south, so hopefully you will have a vague idea which direction is north already. Or use the sun as a guide, remember the sun rises in the east and sets in the west.
Once you know which direction is north, simply orient your weather vane so that your compass rose is properly aligned.
Weather Science for Kids
The way the weather vane works is that the wind is more likely to push the tail end of the arrow than the point end since the tail end has greater surface area. The wind pushes the tail in the direction it is blowing, causing the arrow to point in the direction the wind came from. Kids can test this by simply blowing on the weather vane and seeing how the arrow always turns to point back at them. Have fun watching your kids be young meteorologists!
