MORE INFORMATION- EL NINO

The 1990’s in eastern Australia

Australia did not experience the extremes in weather patterns and climatic conditions again until the early 1990’s.  In 1990-91, the wet season produced a huge amount of rain and yet it almost completely failed the following year as drought set in across Queensland and New South Wales once more.  This was a time of extremes when it came to the weather patterns.  While drought continued in many areas through 1992 and 1993, many people in southeast Australia experienced floods in the springs of 1992 and 1993, and the cool summers which followed.

The period from 1991 to 1995 was considered to be a weaker El-Niño event than the 1982/83 event, but its effects were much longer-lasting.  Southern states, like Victoria and Tasmania, were not seriously affected by drought, due to the weakness of the event, but Queensland and inland New South Wales suffered a long devastating drought for the full four years of El-Niño.  In 1996 a La-Niña event provided welcome relief and some much needed rain.  Unfortunately it was not to last and El-Niño returned again in mid-1997, beginning with a warming of the surface oceans off Peru and Ecuador, this was then followed in mid-1998 by the return of La Niña.  These extreme fluctuations were difficult to manage as farmers especially went from no rain to floods (both of which caused major damage and problems to their livelihoods).

A strong effect was experienced over much of Queensland with about three-quarters of the state recording rainfall totals of ‘very much below average’ (technically speaking, in ‘Decile 1’) for the 9 months from March to November 1991 (see the map in Figure 3 below).  It was the driest such period on record in parts of the Darling Downs area.  The northern half of NSW was also badly affected with about half this region experiencing rainfall ‘very much below the average’ (i.e. in ‘Decile 1’) for the nine months straight. The Central Coast of New South Wales was also affected by the dry conditions but not quite as badly as the north. In Victoria, southern NSW, and much of Tasmania, a very dry autumn was followed by a wet June-Sept period and then below average falls in Oct-Nov.  



Figure 1:  A map of Australia showing rainfall deciles for the period from 1 March to 30 November 1991 (Source: Australian Bureau of Meteorology, ENSO Wrap-Up)

Above to very much above average rain fell in December over SE Qld and the eastern half of NSW marking the beginning of the end of this event in these regions (see the map in Figure 2 below).



Figure 2:  A map of Australia showing rainfall deciles for the period from 1November, 1991 to 30 April, 1992
(Source: Australian Bureau of Meteorology, ENSO Wrap-Up)

Although rainfalls were irregular in January 1992, heavy rain fell again in February, particularly in the southeast of Queensland and NSW with some areas recording their highest rainfall on record up to that time.  The Central Coast of NSW benefited from average to much above average rainfall conditions in this late summer early autumn period.

In the tropics though, totals were consistently below average from November through to April with many areas across the north of Australia recording rainfall ‘very much below the average’ (i.e. in ‘Decile 1’) for the 6 month period.  This consistently below average rainfall throughout the majority of Australia had wide-ranging effects on primary industries as many crops were either flooded or in severe drought for long periods of time.