Student Rainfall Measurement Experiment — Overview

What is this experiment?

You place a simple rain collector at your home, school, or neighborhood. Every day you measure the rain that fell directly from the sky, write down the result, empty the collector, and put it back. Once a week you submit all of your measurements in one report. When many students across Bangladesh measure rain the same careful way, the combined numbers show how rainfall changes from one street, one upazila, and one district to another — real observations collected by ordinary people, which scientists call citizen science.

Our standard

The goal is not perfect weather-station data. It is careful, honest, and comparable student observations. An honest "I missed today" is worth more to science than an invented number.

What you will investigate

• How much rain falls at your own location, day by day and week by week.
• How rainfall differs between neighborhoods, districts, and divisions.
• Whether heavy rainfall matches the flooding or waterlogging you see nearby.
• How much useful water could be collected from a typical roof.

The main research question: How much direct rainfall does your location receive, and how does it compare with rainfall measured by other students at other locations?

Direct rainfall vs. runoff

Your collector must catch only drops falling straight from the sky. Water that flows or splashes from a roof, tree, wall, pipe, or flooded ground is runoff, and it makes your measurement bigger than the true rainfall — so it must never enter your collector. Remember: direct rain from the sky, YES; water from roofs, trees, walls, pipes, or floods, NO.

What "1 millimeter of rain" means

One millimeter of rainfall is a layer of water 1 mm deep on a flat, level surface. Rainfall is always reported in millimeters, never in liters. As a rule of thumb, 1 mm of rain falling on 1 square meter is about 1 liter of water.

The weekly cycle

Observe → Measure → Record → Reset → Report → Analyze. Inspect the collector before touching it, read the water depth in millimeters at eye level, record the result and any problems right away (including 0.0 mm on dry days), empty and return it to the same clean, level position, submit all seven daily entries together at the end of the week, then use your valid readings to find totals, patterns, and roof-water potential.

Scientific honesty

A missing measurement is not zero. An overflow is not an exact number. A knocked-over collector is not valid data. Reporting a problem honestly is more scientific than inventing a value.

What you will learn

• Measurement skills — units, precision, and consistent procedure.
• Mathematics — totals, averages, percentages, and comparisons with real data you collected.
• Graphing and interpretation — turning numbers into pictures and conclusions.
• Quality control — deciding when data can be trusted and when it cannot.
• Water awareness — how much rain your community receives and how it could be preserved.

Safety first

Never climb onto roofs, trees, walls, or unsafe structures, and never go outside during lightning, dangerous wind, or flooding. A measurement is never worth an injury — wait until conditions are safe and ask an adult for help when needed.

Where this method comes from

The protocol follows the same principles used by professional and volunteer rain observers around the world, including the World Meteorological Organization's Guide to Instruments and Methods of Observation (WMO-No. 8) and the CoCoRaHS community precipitation network.

This is a summary. Download the attached PDF below for the complete, print-ready document. Grades 9–12 · Bangladesh · Student field research — measure carefully, report honestly, learn from local rain.