How to Read a Rain Gauge

A rain gauge is used to keep track of the amount of rain that falls in an area over a given period of time. The depth of rainwater collected inside a rain gauge is measured in inches or centimeters.

• To get an accurate reading of the rainfall collected in your rain gauge, you must be at eye level with the top of the water. If the gauge is attached too high for you, have an adult help by pulling it off the nails or Velcro attaching the plastic to the wood.
  
  
• Compare the top of the water level to the printed scale on the tube's front. Look at the example to the right. The blue numbers to the left of the tube is rainfall in inches. The water level is two small lines above the big number one, which means the tube collected 1.2 inches of rain. If the water level doesn't match a line on the scale, round to the closest line.
  
  
• After taking the measurement, dump out the water and reattach the tube to the fence, post, or stick.
  

A Few Notes on Record Keeping

• Measure the rainfall every day at about the same time of day. The more detailed and accurate your measurements, the more specific your record of rainfall pattern.
  
  
• Have fun keeping record of the month's rainfall. A printable data sheet with an example entry is available for your use. [Adobe Acrobat Reader needed to print. If you need to download (free), click the link below.] A ruled notebook is also a good place to record measurements. You may want to include notes on other climate observations, such as temperature, wind direction, cloud types, etc.
  



• Share your rainfall records with others who visit the Rain Check website. You can submit your daily rainfall totals, see your entries and search others' in the online database. You also can find links to other weather and climate websites in the online resource listing. Be a part of the ISWS Rain Check Network!
  
  
• At the end of the week, add up the totals to see how much fell in one week. Do the same at the end of two weeks, etc. At the end of the month, add up the totals to see how much rain fell in that month. Continue recording the total amount of rainfall received in each month. Which month was the rainiest? Which month was the driest?
  
  
• If you move your rain gauge to different places around your yard, sure to record the locations of your rain gauge measurements. Where you place your gauge can have a big effect on the rainfall amount you collect. Have fun comparing rainfall amounts from different spots around your yard. Where does the most rain fall? What locations are the driest?
  
  
• Compare the rainfall levels in your neighborhood with amounts recorded for your city. TV weather reports, newspapers, and numerous web sites list daily, weekly, or monthly rainfall totals. Historical climate summaries are also available in the online resources section of the Rain Check Network webpage.

• A printable reference guide summarizing the above information is available.[Adobe Acrobat Reader needed to print (free). If you need to download, click the link below.]