Annoted example graph of rainfall history.

The rolling five-year average is calculated by averaging the rainfall figures for the previous five years to get the figure for that year. For example, the 1970 figure is the average of 1966, 1967, 1968, 1969 and 1970. The rolling five-year average is useful because the effects of rainfall (either high or low) do not stop at the end of the calendar year, so a graph of annual rainfall for each year can be misleading. Importantly, the rolling five-year average is a better indicator of trends in rainfall.

in California, so here is a graph of annual rainfall in Los Angeles

Example graph of monthly rainfall history. (Annotations have been added to this example.)

Thumbnail link to graph of rainfall in Sahel


elow is a graph of rainfall between 1952-2010 that was created by Bobbi Kimball. Click on the image to see a detailed accounting of monthly rainfall totals for Bolinas from (these totals are not official totals, rather they were taken by individuals in the community and are subject to some margin or error).

The following is an example bar graph of rainfall and stomata counts.

Graphs can provide a quick overview of wet and dry periods. Below is a small view of the annual rainfall graph for Bungaree, near Ballarat, Victoria. It shows rainfall history back to the 1881. The gaps are years with insufficient data.
have been added to this example, marking some of the historic Australian drought years, as well as the driest and wettest year at Bungaree during this time range.
You can also view graphs for each month, for example: .
Graphs of daily rainfall totals for each year are also available, for example:

Example graph of monthly rainfall history. (Annotations have been added to this example.)
Graphs can provide a quick overview of wet and dry periods. Below is a small view of the annual rainfall graph for Bungaree, near Ballarat, Victoria. It shows rainfall history back to the 1881. The gaps are years with insufficient data.
have been added to this example, marking some of the historic Australian drought years, as well as the driest and wettest year at Bungaree during this time range.
You can also view graphs for each month, for example: .
Graphs of daily rainfall totals for each year are also available, for example:

Each day of the show is represented by a bottle sandblasted with that days date. The current day’s bottle is placed under a flask. If it rained or snowed that day, the precipitation is funneled into the gallery. After 24 hours, the bottle is capped and placed back into the calendar, a series of five glass shelves representing each month. By the end of the show, the piece had created a bar graph of rainfall for each week. photo of stollers on the Brooklyn Heights promenade (NYT/Chester Higgins Jr.); graph of rainfall amounts for the month of May from '82 to '88 (Source: National Weather Service) (pg. B4)
A monthly graph of rainfall as a 12-month departure from mean shows deficits lasting longer than surpluses in recent history.

Graph of Rainfall at Indianapolis from June 1-July 27

(ii) The Rainfall Anomaly Index. shows the graph of Rainfall Anomaly Index against the years of record. It can be seen from this figure that the Rainfall Anomaly Index exhibits linear trend; the linearity tapers off at lower index values indicating slightly different responses to more severe drought. The year 1934 had the highest Rainfall Anomaly Index while 1942 had the least. Figure 4 shows that drought occurred in the study area throughout the 73 years of record. 30 years out of the 73 years had positive Rainfall Anomaly Index values while the remaining 43 years had negative Rainfall Anomaly Index values. Since the anomalies decrease down the graph as shown in , therefore the years with negative anomaly index values experienced more severe drought than those years with positive anomaly index. The significance of the two curves in shows that the anomaly index either positive or negative has almost the same drought period. Also, the rainfall values decrease down the graph.

ALN 49: Taylor: Fig. 1: Graph of Sahelian rainfall during 20th century

Fluctuation graph of rainfall data for the Period of

The rolling five-year average is calculated by averaging the rainfall figures for the previous five years to get the figure for that year. For example, the 1970 figure is the average of 1966, 1967, 1968, 1969 and 1970. The rolling five-year average is useful because the effects of rainfall (either high or low) do not stop at the end of the calendar year, so a graph of annual rainfall for each year can be misleading. Importantly, the rolling five-year average is a better indicator of trends in rainfall.

Below is a graph of rainfall between 1952-2010 that was created by Bobbi Kimball

Graph of rainfall in San Diego, 1851-2002

This graph of rainfall totals posted on Twitter by the National Weather Service in Phoenix shows just how unevenly spread the monsoon moisture can be.