Mesonet Annual Rainfall Graphs

This activity will make use of a tool that lets you plot monthly rainfall totals for any year and any Mesonet station of your choice. Please note that if you use the current year, it will only chart those months that have completely passed. Monthly rainfall total plots are useful for climate studies, agricultural decision making, and water resource management. For example, if a given month was particularly dry a farmer will know to irrigate and water reservoir operators might decide to close off their dams to conserve water.

To decide whether a given month was exceptionally dry or wet, you should compare it to a climatological average. These are computed by taking 20 to 30 years of rainfall totals for a given month and averaging them out for that month. This is repeated for each of the 12 months. The result can be plotted in a so-called climograph. We have done this for you for stations where a long enough climate record exists and the results can be found here. We have picked out stations that are in the same general area as the Mesonet. The data was provided by NOAA´s National Climatic Data Center (

Select a Mesonet station and a year below and hit GO to plot your chart. Then go to the climograph site (maybe using another tab on your browser so you can go back and forth easily) and pick an NCDC site close to your site. Do any of your months look particularly wet or dry compared to the climograph? (Notice that if insufficient data was collected from a station in a praticular month to accurately represent the total, the name of the month will be displayed in red)

Station:   Year:   Units: