Science Fun

Rain, Rain, Don’t Go Away Rain Gauge



  • 2 liter plastic bottle
  • Scissors
  • Duct tape
  • Sand
  • Sharpie Marker
  • Ruler


  1. Empty and wash out the 2 liter bottle so it’s nice and clean.
  2. Take the scissors and cut off the spout top right where the taper or curve begins.
  3. Fill bottom of the bottle with 1/2 inch of sand. This will keep the bottle from falling over on those windy days.
  4. Pour in just enough water so you can see the water level above the sand. Yes, your sand will be wet! This is called your saturation point.
  5. Use the Sharpie Marker to draw a line at the saturation point above the sand. Next to the line write “starting point”.
  6. Line the ruler up (from the starting/saturation point) and draw a line for every inch up to the top of the bottle.
  7. Take the top “cut off” spout portion of the bottle and flip it upside down. Insert it into the bottle and use some duct tape to secure it. This part will help catch and collect the rainfall by funneling into your bottle.
  8. Now it’s time to find a good place for your rain gauge outside and record your rain data.

How it Works:

The rain gauge collects water. When the water drips or pours into your rain gauge you can accurately measure how much rainfall has occurred.

Extra Experiments:

  1. Make multiple rain gauges. Place one in an open area outside, one underneath a tree, and one by edge of your roof. Are you getting different measurements of rainfall? If so, why do you think that is? And which one do you think is the most accurate reading?
  2. Add 1/4, 1/2, 3/4 inch spots onto your rain gauge so you get a more specific and accurate reading.