Rainfall for September, 1985 - 1999

Rainfall & snowfall are important to study as these are the main source of fresh water to the land. Many agricultural corps we grow are dependent on rainfall for their growth. One of the impacts of a changing climate is the amount of water vapour in the atmosphere. For every 1oC increase in temperature there a 6-7% increase in water vapour carrying capacity of the atmosphere, and this will fall as rain/snow at some point on the earth. The challenge is predicting where it will fall and how much.

The models we use are our best tools for predicting where rainfall will occur and for how long (eg light drizzle or thunder storm). However the models need good input data and the rainfall maps shown here were constructed with observation corrected data. By breaking down the information by month and looking at 15 years for a single month we can observe year to year changes.

Precipitation varies not only within a calendar year but also from year to year, and there are known trends such as El Niño events that occurs every 2-7 years. (http://www.elnino.noaa.gov/). For example over Eastern Australia and Indonesia dryer conditions are apparent in July 1987 compared to July 1986 or 1988. This is because 1987 was an El Niño year resulting in dryer conditions in this region of the globe and 1988 was a La Niña year which favours wetter conditions.

Identifying patterns in rainfall/snowfall changes will help researches to better understanding of what changes are occurring and increase our knowledge of the how the water cycle operates.

Average Total Rainfall (mm/yr)

Bargraph referencing the colours on the rainfall maps.

Other Maps

Rainfall Maps