People who study climate are called climatologists. Climatologists use temperature and precipitation records to define what a place’s “normal” climate is like. They do this by averaging 30 years of temperature and precipitation records. They also keep track of this information by making climographs for cities and regions.
is a graph that shows monthly average temperature and precipitation for a place. The graph to the left is an example of a climograph for Chicago, Illinois. The green bars show the amount of precipitation each month, and the red line shows the average temperature each month. See more climographs for U.S. cities
and cities around the world
Climatologists can also look back through years of records to determine how often droughts happen in a specific city or region. Remember, drought can happen anywhere, but it may happen more often in some areas than in others!
A rain gauge helps us keep track of how much rain we get, but keeping track of drought isn’t that simple. Climatologists use many different indicators to monitor (watch) when drought begins and ends and also how severe the drought is. Temperature and rainfall are indicators, but so are water levels in streams, rivers, and lakes, the amount of moisture in the soil, and the amount of snowpack in the mountains.
Climatologists compare this information with what is “normal” for an area to determine whether a drought is beginning or ending, or even how bad the drought might be. For example, doctors have calculated that a person’s normal body temperature is 98.6 degrees Fahrenheit. If you aren’t feeling well, the doctor or your parents will take your temperature. How much above or below normal (98.6°F) it is can indicate how sick you might be. Climatologists do the same thing to let people know if there is a drought and how severe the drought is.