This graph of the rainfall in Nagoya Japan, is used here only to illustrate how you can tabulate the results of the rainfall in your area. Mr. Okazaki was interested to know, just how much rain falls, on average, in his location, both monthly and yearly. As you can see, the rainfall in Nagoya is quite heavy and consistent throughout the last 28 years.

On the figures shown here above, it is reasonable to assume that his tanks would not run dry if the average rainfall was achieved. The peak in July/August indicates the 'Wet' or 'Rainy' season in Japan. The rainfall then, would almost equal Western Australia's rainfall for the whole year.