Weather 101 For Kids (fun and easy weather experiments!)

Make a Thermometer

Supplies:

• Water bottle
• Tap water
• Rubbing alcohol 
• Food coloring
• Clear plastic drinking straw
• Modeling clay

Experiment:

1. Pour equal parts of tap water and rubbing alcohol into the bottle, filling about 1/8 to a 1/4 of the bottle.
2. Add a couple of drops of food coloring and mix.
3. Put the straw in the bottle, but don’t let the straw touch the bottom.
4. Knead the modeling clay and use it to seal the neck of the bottle, so the straw stays in place.
5. Now hold your hands on the bottle and watch what happens to the mixture in the bottle.
6. When it is at ambient temperature (the current temperature in your space), make a mark on your bottle where the water line is in the straw. That is where your room temperature line is! That is usually around 68 to 70 degrees.
7. You can calibrate your thermometer with the temperature in your house.

But Why!?

This thermometer works by air pressure. As the air in the bottle heats up. the molecules expand. When the air molecules expand, it pushes the liquid up the straw. As the air cools, it contracts, allowing the liquid to travel back into the bottle. 

Wind Chill-y Hands

Supplies:

• Hand sanitizer
• Hands (or foot or elbow…)

Experiment:

1. Wave your hands in the air.
2. Notice how it feels.
   Is it cold?
   Is it colder than they were feeling before? 
3. Now, pour a bit of hand sanitizer into your hand and rub your hands together to cover your hands with the hand sanitizer.
4. Wave your hands in the air again.
   
   Do you notice a difference?  

But Why!?

The first time you wave your hands, it doesn’t really feel much different from when your hands are just by your sides. Maybe you feel a little breeze, but that’s about it. However, when you wave your hands in the air with hand sanitizer on them, it feels much colder because the air around your hands that you had warmed up by your body is being used up to evaporate the hand sanitizer.

Wind does the same thing, it blows away the layer of heat that your body creates around you, so now your body has to keep heating up the air around you, causing you to feel colder! 

Weather Vane

Supplies:

• Pencil (with an eraser)
• Straw
• Straight pin
• Scissors
• Heavy Paper or cardboard
  • You will cut out one triangle and one square
    The square needs to be larger than the triangle.
• A lump of modeling clay or play dough
• Paper plate
• Something to write with
• Compass (or app on your phone) for calibration

Experiment:

1. Make a large + on the paper plate (from side to side) and mark the directions on the plate. If you think of it like a clock, North is at 12, East is at 3, South is at 6, and West is at 9.
2. Cut slits in both ends of the straw. The slits should be going the same direction as each other.
3. Slide the triangle piece of paper into one slit and the square into the other. Your straw will look a bit like an arrow.
4. Put your clay in the center of the + on your paper plate and stick the pencil tip into the clay.
5. Push the pin through the center of the straw (or as close to center as possible, use a ruler if necessary) and into the eraser of the pencil. 
   Allow a bit of space above and below the straw so it isn’t pushed too tightly into the eraser.
   ** Make sure the straw can pivot around on the pin and move freely to follow the wind.
6. Set the plate down on a flat surface with the directional markings aligned to the correct directions. (use a compass or compass app to help)
7. Put your weather vane in a windy place and see it point to the direction that the wind is COMING from!

But Why!?

The weather vane actually points to the direction that the wind is COMING from and not in the direction that the wind is blowing. The arrow is the reason we are able to see this.

The wind pushes the arrow into a straight line along the wind path, but how does it know which direction to turn? Since the point of the triangle is more aerodynamic than the square tail, it cuts through the wind easier facing towards the wind with the larger tail trailing.