Climate trends - Pilbara
The Pilbara region extends from Exmouth to around 300 km east of Port Hedland and inland to Newman. The Pilbara region is a subdivision of the arid region located in the subtropics.
The region is characterised by dry winters and relatively wetter summers. Summer rainfall is sporadic and variable, resulting from tropical cyclone activity. Average annual rainfall is relatively low (200–400 mm) and mostly falls in bursts of intense rainfall over summer (December–March), and declines from 300–350 mm in the north-east to less than 250 mm in the south and west.
Past observations
There has been a significant increase in annual rainfall, especially in the eastern part of the Pilbara, and rainfall variability between years. For example, from 1995 to 2001, there was an exceptionally wet 7-year period with a mean annual rainfall of 500 mm when WA experienced more tropical cyclones than average. Winter rainfall has decreased in the western Pilbara because cold fronts have progressively not reached as far north since the mid-20th century.
Future climate projections
Rainfall could increase or decrease in the future. The wettest case global circulation model results project a 3 per cent increase in average annual rainfall for the region at 2050, while the driest case shows a 10 per cent reduction.
The majority of climate change projections indicate tropical cyclones may become less frequent overall but that the strongest tropical cyclones may increase in intensity and size and travel further south.
