At-Home STEM Activities: Make a Rain Gauge
Turn April showers into an opportunity for at-home science! In this all-ages activity, learn how to track rainfall using a simple homemade rain gauge.
Adult supervision required—sharp objects utilized in one step.
Materials:
Empty 1- or 2-liter plastic bottle
Stones or marbles
Scissors or knife
Permanent marker
Masking, duct, or painter’s tape (optional)
Process:
Remove the label from the empty plastic bottle, and dispose of the cap
Have AN ADULT carefully use scissors or a knife to cut the top off of the bottle, starting just where the bottle starts curving inward toward the cap. The plastic edges may be sharp—handle with care!
Place a few stones or marbles into the bottom of your bottle. This will weigh down your gauge when it is outside.
Turn the top portion of the bottle upside-down and place it into the neck of the bottom section, pointing downward. This will serve as a funnel, directing rainfall into your gauge. If desired, use tape (e.g. painters, duct, or masking tape) to secure the two pieces of the bottle together and cover sharp edges.
Pour a small amount of water into the bottle, until it just covers the top of the stones or marbles.
Hold a ruler to the side of your gauge, making sure that the 0 point lines up with the top of the water. You have just calibrated your gauge to measure all rainfall beginning at the top of the water (versus at the bottom of the bottle).
Use a permanent marker to make a mark every 1/2 centimeter from zero (the top of the water) to the bottom of the funnel. We drew a line at every full centimeter and a dot at every half-centimeter.
Turn the bottle 1/4 turn and repeat this process, making a mark every 1/2 inch. Again, we used lines for whole inches and dots for half-inches.
Place your gauge in a secure location outside. Choose somewhere with no overhead obstructions (nothing to prevent rain from reaching the funnel), and where it is not likely to be disturbed or knocked over by pets, wind, etc.
Record Your Data
Create a log or a table to track rainfall in your area. For each entry, you’ll want to record the date, your rainfall measurement, and maybe even a sketch of the cloud cover that day. What other data might you want to record in your rain log?
Process:
Keep your eyes on the daily weather forecast, or look at the sky each morning. Do you expect a lot of rainfall today? Can you predict how much?
Re-calibrate your gauge each morning: empty out all of the water until it’s level with the zero-mark. If the weather has been very dry, you may have to ADD a small amount of water to get up to the zero-mark, to make up for evaporation that occurred overnight.
Take a measurement at the same time every evening, to see how much rain fell during the day. Make a note in your log of how many centimeters and how many inches of rain fell over the course of the day.
Take daily measurements for one week, two weeks, or one month. Do you see patterns emerging? Does your ability to predict daily rainfall based on cloud cover become more accurate over time? Why do you think that is?
