Our climate

What was cool then, isn't so cool now

A bit like our climate. August might have been wet but overall, Perth’s rainfall is inconsistent and average temperatures are increasing. So please, think about your water. Every drop is precious.

Save water this spring

The facts

Rainfall

Rainfall

We used to get around 750 mm of rain a year on average; however these days we only get around 688 mm.

Temperatures

Temperatures

The average overnight minimum temperature has increased by 1.1 degrees Celsius (°C) since 1910.

Streamflow

Streamflows

We used to get around 338 GL of inflows into our dams, but these days we only get around 42 GL.

Rainfall

Rainfall

We used to get around 750 mm of rain a year on average; however these days we only get around 688 mm.

Temperatures

Temperatures

The average annual temperature in the South-West of WA has increased by 1.1 degrees Celsius (°C).

Streamflow

Streamflows

We used to get around 338 GL of inflows into our dams, but these days we only get around 42 GL.

Save water this spring

Some extra facts to absorb

While it may feel like we’ve had a lot of rain this winter, we are still only just above the year-to-date average.

As our catchments are so dry following nearly 20 years of abnormally dry weather, we’d need to get double the average rainfall for years on end to fill our dams again.

We need steady, regular rain in order to soak our catchments and get water flowing into our dams. Slowly declining rainfall means Perth's dams receive much less streamflow than in past years. Streamflow is the amount of water entering our dams from our catchments and is measured by changing water storage levels.

Between 1910 and 2013, the average annual temperature has increased by 1.1 degrees Celsius (°C), with similar increases in average daily maximums and minimums.

While this doesn’t seem like much, even a small increase in temperatures can present significant environmental, social and economic challenges to WA.

Overall, Australian temperatures are projected to continue increasing with more extremely hot days and fewer extremely cool days.

While it may look like dam levels are increasing, this may not be the result of rainfall and streamflow. The water in our dams is no longer just made up of inflows from rain. We store Groundwater and desalinated water in our dams during periods of low demand so it’s available when it’s needed most – in the hotter, drier months.

We’ve developed innovative solutions to Perth’s changing climate, like desalination and groundwater replenishment, but customers will always have a role to play.

A long term, sustained focus on using less water is central to living with less rainfall and becoming climate resilient. That’s why reducing our water use has always been a part of our long-term plan to secure our water future for generations to come.

Using less water minimises the amount of groundwater we have to abstract and our energy use associated with producing other water sources like desalination. It defers the costs of investing in new water sources and infrastructure and the price increases which come with this.

Our average per person water use has decreased over recent years but Perth still remains one of the highest water using cities in Australia.

Spring brings with it generally milder weather than Perth experiences in the height of Summer, so Spring is the best time to take action to save water. There are small things we can all implement inside and outside our homes to ensure we are saving water for when we need it most. Like putting a bucket in your shower to catch water, or turning off the tap when you brush your teeth. You can see more water saving tips here.