Directions
Once the title and the labels are sorted out, it’s time to move on to the structure of the graph. Many graphs are built on just two axes (plural of axis, pronounced ACK-sees). The axes are like two rulers that form the framework of the graph. As a rule of thumb, the x-axis is the horizontal ruler that sits on the bottom. The y-axis is the vertical ruler ("the y points to the sky").
Like a ruler, each axis has evenly spaced tick marks that count off whatever is being measured. Each tick mark can represent anything from a millisecond to a thousand years, or from a bushel of corn to a ton of oil. The axis label and the scale will tell you what each axis measures. In this example, the scale on the y-axis shows that each tick mark represents one inch of rainfall. On the x-axis, the scale is one tick mark for one month.
Some parts of the scale have fallen off the axes from the graph on the right. Drag and drop the lost months and numbers to return each to its place on the correct axis.
Source: National Climatic Data Center, 1981-2010 Climate Normals