Supplies:

• Plastic Bottle
• Scissors
• Ruler
• Marker
• Duct Tape

1. Take your plastic bottle and, using the scissors, carefully cut off the top of the bottle about where the bottle starts to narrow. This can be tricky (and sharp!) so have an adult nearby to help you.
2. Place the cut-off bottle top upside down in the bottom half of the bottle to make a funnel. If you need to, use some tape to secure the funnel. This funnel helps to prevent evaporation of the rain water before you get a chance to take measurements.
3. Place your ruler next to the bottle and, using a pen, mark and label every centimeter (cm) up the side of the bottle. You can also measure in inches (in) and mark quarter or half inches. If you’re having trouble getting your marker to write on the plastic, place a strip of duct tape on the bottle and write on that!
4. Your rain gauge is done! Find an open spot outside for it to collect rain. Make sure the bottle is secured so wind doesn’t blow it away. You can bury the bottom half underground, wedge the bottle between two objects, or dump a handful of small pebbles into the bottom to anchor it down.
5. Wait until it rains and then make some observations with your brand new rain gauge!

1. How could you use a rain gauge in your garden?
2. Is the bottom of your bottle flat or filled with pebbles? How might this affect your measurements when collecting rain? How could you change your rain gauge to get more accurate measurements?
3. Time how long a rain storm lasts and compare that to the amount of rain in your gauge. Record your observations and repeat over the next few rain storms. Did it rain a whole bunch in a short period of time? Did it rain all day but your gauge still didn’t fill up that much?