M
E
N
U
climate change wa

Western Australia temperature archive since 2009

Below archives rolling 12 month average temperatures recorded at Western Australia's 32 oldest weather station locations since 2009.

Year to March 2009

min .29C above the early 1900s

max .68C above the early 1900s

Year to April 2009

min .33C above the early 1900s

max .79C above the early 1900s

Year to May 2009

min .25C above the early 1900s

max .75C above the early 1900s

Year to June 2009

min .29C above the early 1900s

max .69C above the early 1900s

Year to July 2009

min .31C above the early 1900s

max .64C above the early 1900s

Year to August 2009

min .51C above the early 1900s

max .72C above the early 1900s

Year to September 2009

min .44C above the early 1900s

max .60C above the early 1900s

Year to October 2009

min .39C above the early 1900s

max .60C above the early 1900s

Year to November 2009

min .53C above the early 1900s

max .92C above the early 1900s

Year to December 2009

min .59C above the early 1900s

max 1.09C above the early 1900s

Year to January 2010

min .54C above the early 1900s

max 1.16C above the early 1900s

Year to February 2010

min .60C above the early 1900s

max 1.28C above the early 1900s

Year to March 2010

min .75C above the early 1900s

max 1.37C above the early 1900s

Year to April 2010

min .80C above the early 1900s

max 1.35C above the early 1900s

Year to May 2010

min .85C above the early 1900s

max 1.29C above the early 1900s

Year to June 2010

min .80C above the early 1900s

max 1.31C above the early 1900s

Year to July 2010

min .74C above the early 1900s

max 1.32C above the early 1900s

Year to August 2010

min .63C above the early 1900s

max 1.27C above the early 1900s

Year to September 2010

min .63C above the early 1900s

max 1.34C above the early 1900s

Year to October 2010

min .56C above the early 1900s

max 1.34C above the early 1900s

Year to November 2010

min .56C above the early 1900s

max 1.37C above the early 1900s

Year to December 2010

min .61C above the early 1900s

max 1.23C above the early 1900s

Year to January 2011

min .68C above the early 1900s

max 1.17C above the early 1900s

Year to February 2011

min .72C above the early 1900s

max 1.02C above the early 1900s

Year to March 2011

min .69C above the early 1900s

max .95C above the early 1900s

Year to April 2011

min .67C above the early 1900s

max .95C above the early 1900s

Year to May 2011

min .69C above the early 1900s

max .93C above the early 1900s

Year to June 2011

min .75C above the early 1900s

max .94C above the early 1900s

Year to July 2011

min .88C above the early 1900s

max .96C above the early 1900s

Year to August 2011

min .97C above the early 1900s

max 1.05C above the early 1900s

Year to September 2011

min .96C above the early 1900s

max 1.06C above the early 1900s

Year to October 2011

min 1.07C above the early 1900s

max .99C above the early 1900s

Year to November 2011

min 1.04C above the early 1900s

max .84C above the early 1900s

Year to December 2011

min 1.10C above the early 1900s

max 0.88C above the early 1900s

Year to January 2012

min 1.09C above the early 1900s

max .81C above the early 1900s

Year to February 2012

min .99C above the early 1900s

max .85C above the early 1900s

Year to March 2012

min .99C above the early 1900s

max .86C above the early 1900s

Year to April 2012

min .86C above the early 1900s

max 0.89C above the early 1900s

Year to May 2012

min .79C above the early 1900s

max .95C above the early 1900s

Year to June 2012

min .78C above the early 1900s

max .95C above the early 1900s

Year to July 2012

min .57C above the early 1900s

max .96C above the early 1900s

Year to August 2012

min .48C above the early 1900s

max 0.97C above the early 1900s

Year to September 2012

min .54C above the early 1900s

max 1.06C above the early 1900s

Year to October 2012

min .54C above the early 1900s

max 1.22C above the early 1900s

Year to November 2012

min .52C above the early 1900s

max 1.25C above the early 1900s

Year to December 2012

min .53C above the early 1900s

max 1.35C above the early 1900s

Year to January 2013

min .54C above the early 1900s

max 1.44C above the early 1900s

Year to February 2013

min .56C above the early 1900s

max 1.56C above the early 1900s

Year to March 2013

min .61C above the early 1900s

max 1.46C above the early 1900s

Year to April 2013

min .79C above the early 1900s

max 1.56C above the early 1900s

Year to May 2013

min .92C above the early 1900s

max 1.49C above the early 1900s

Year to June 2013

min .89C above the early 1900s

max 1.49C above the early 1900s

Year to July 2013

min 1.01C above the early 1900s

max 1.51C above the early 1900s

Year to August 2013

min 1.14C above the early 1900s

max 1.53C above the early 1900s

Year to September 2013

min 1.24C above the early 1900s

max 1.46C above the early 1900s

Year to October 2013

min 1.21C above the early 1900s

max 1.42C above the early 1900s

Year to November 2013

min 1.31C above the early 1900s

max 1.51C above the early 1900s

Year to December 2013

min 1.23C above the early 1900s

max 1.47C above the early 1900s

Year to January 2014

min 1.17C above the early 1900s

max 1.43C above the early 1900s

Year to February 2014

min 1.12C above the early 1900s

max 1.29C above the early 1900s

Year to March 2014

min 1.17C above the early 1900s

max 1.31C above the early 1900s

Year to April 2014

min 1.01C above the early 1900s

max 1.19C above the early 1900s

Year to May 2014

min 1.08C above the early 1900s

max 1.22C above the early 1900s

Year to June 2014

min 1.03C above the early 1900s

max 1.24C above the early 1900s

Year to July 2014

min 1.07C above the early 1900s

max 1.22C above the early 1900s

Year to August 2014

min 1.03C above the early 1900s

max 1.29C above the early 1900s

Year to September 2014

min 1.03C above the early 1900s

max 1.41C above the early 1900s

Year to October 2014

min 1.10C above the early 1900s

max 1.46C above the early 1900s

Year to November 2014

min 1.02C above the early 1900s

max 1.41C above the early 1900s

Year to December 2014

min .99C above the early 1900s

max 1.35C above the early 1900s

Year to January 2015

min .98C above the early 1900s

max 1.37C above the early 1900s

Year to February 2015

min 1.09C above the early 1900s

max 1.56C above the early 1900s

Year to March 2015

min 1.07C above the early 1900s

max 1.46C above the early 1900s

Year to April 2015

min 1.05C above the early 1900s

max 1.45C above the early 1900s

Year to May 2015

min .83C above the early 1900s

max 1.37C above the early 1900s

Year to June 2015

min .88C above the early 1900s

max 1.43C above the early 1900s

Year to July 2015

min .98C above the early 1900s

max 1.49C above the early 1900s

Year to August 2015

min .97C above the early 1900s

max 1.34C above the early 1900s

Year to September 2015

min .83C above the early 1900s

max 1.31C above the early 1900s

Year to October 2015

min .88C above the early 1900s

max 1.43C above the early 1900s

Year to November 2015

min .98C above the early 1900s

max 1.54C above the early 1900s

Year to December 2015

min .99C above the early 1900s

max 1.57C above the early 1900s

Year to January 2016

min 1.07C above the early 1900s

max 1.50C above the early 1900s

Year to February 2016

min .93C above the early 1900s

max 1.38C above the early 1900s

Year to March 2016

min 1.02C above the early 1900s

max 1.41C above the early 1900s

Year to April 2016

min 1.13C above the early 1900s

max 1.50C above the early 1900s

Year to May 2016

min 1.21C above the early 1900s

max 1.55C above the early 1900s

Year to June 2016

min 1.16C above the early 1900s

max 1.38C above the early 1900s

Year to July 2016

min 1.11C above the early 1900s

max 1.30C above the early 1900s

Year to August 2016

min 1.03C above the early 1900s

max 1.20C above the early 1900s

Year to September 2016

min .95C above the early 1900s

max .97C above the early 1900s

Year to October 2016

min .72C above the early 1900s

max .68C above the early 1900s

Year to November 2016

min .58C above the early 1900s

max .64C above the early 1900s

Year to December 2016

min .56C above the early 1900s

max .58C above the early 1900s

Year to January 2017

min .40C above the early 1900s

max .57C above the early 1900s

Year to February 2017

min .36C above the early 1900s

max .39C above the early 1900s

Year to March 2017

min .25C above the early 1900s

max .34C above the early 1900s

Year to April 2017

min .10C above the early 1900s

max .36C above the early 1900s

Year to May 2017

min .06C above the early 1900s

max .44C above the early 1900s

Year to June 2017

min .02C below the early 1900s

max .63C above the early 1900s

Year to July 2017

min .01C below the early 1900s

max .73C above the early 1900s

Year to August 2017

min .08C above the early 1900s

max .83C above the early 1900s

Year to September 2017

min .19C above the early 1900s

max .99C above the early 1900s

Year to October 2017

min .28C above the early 1900s

max 1.06C above the early 1900s

Year to November 2017

min .40C above the early 1900s

max 1.04C above the early 1900s

Year to December 2017

min .43C above the early 1900s

max 1.06C above the early 1900s

Year to January 2018

min .47C above the early 1900s

max 1.01C above the early 1900s

Year to February 2018

min .52C above the early 1900s

max 1.03C above the early 1900s

Year to March 2018

min .59C above the early 1900s

max 1.16C above the early 1900s

Year to April 2018

min .67C above the early 1900s

max 1.25C above the early 1900s

Year to May 2018

min .65C above the early 1900s

max 1.30C above the early 1900s

Year to June 2018

min .69C above the early 1900s

max 1.18C above the early 1900s

Year to July 2018

min .73C above the early 1900s

max 1.23C above the early 1900s

Year to August 2018

min .62C above the early 1900s

max 1.14C above the early 1900s

Year to September 2018

min .55C above the early 1900s

max 1.13C above the early 1900s

Year to October 2018

min .63C above the early 1900s

max 1.11C above the early 1900s

Year to November 2018

min .50C above the early 1900s

max .96C above the early 1900s

Year to December 2018

min .51C above the early 1900s

max 1.01C above the early 1900s

Year to January 2019

min .49C above the early 1900s

max 1.12C above the early 1900s

Year to February 2019

min .49C above the early 1900s

max 1.32C above the early 1900s

Year to March 2019

min .51C above the early 1900s

max 1.31C above the early 1900s

Year to April 2019

min .46C above the early 1900s

max 1.23C above the early 1900s

Year to May 2019

min .38C above the early 1900s

max 1.16C above the early 1900s

Year to June 2019

min .37C above the early 1900s

max 1.17C above the early 1900s

Year to July 2019

min .32C above the early 1900s

max 1.16C above the early 1900s

Year to August 2019

min .36C above the early 1900s

max 1.29C above the early 1900s

Year to September 2019

min .44C above the early 1900s

max 1.42C above the early 1900s

Year to October 2019

min .41C above the early 1900s

max 1.55C above the early 1900s

Year to November 2019

min .45C above the early 1900s

max 1.76C above the early 1900s

Year to December 2019

min .57C above the early 1900s

max 2.01C above the early 1900s

Year to January 2020

min .53C above the early 1900s

max 1.93C above the early 1900s

Year to February 2020

min .60C above the early 1900s

max 1.85C above the early 1900s

Year to March 2020

min .55C above the early 1900s

max 1.83C above the early 1900s

Year to April 2020

min .66C above the early 1900s

max 1.90C above the early 1900s

Year to May 2020

min .73C above the early 1900s

max 1.84C above the early 1900s

Year to June 2020

min .82C above the early 1900s

max 1.98C above the early 1900s

Year to July 2020

min .92C above the early 1900s

max 2.01C above the early 1900s

Year to August 2020

min .99C above the early 1900s

max 1.98C above the early 1900s

Year to September 2020

min 1.19C above the early 1900s

max 1.92C above the early 1900s

Year to October 2020

min 1.17C above the early 1900s

max 1.88C above the early 1900s

Year to November 2020

min 1.20C above the early 1900s

max 1.72C above the early 1900s

Year to December 2020

min 1.05C above the early 1900s

max 1.44C above the early 1900s

Year to January 2021

min 1.15C above the early 1900s

max 1.50C above the early 1900s

Year to February 2021

min .99C above the early 1900s

max 1.38C above the early 1900s

Year to March 2021

min .97C above the early 1900s

max 1.35C above the early 1900s

Year to April 2021

min .88C above the early 1900s

max 1.34C above the early 1900s

Year to May 2021

min 1.03C above the early 1900s

max 1.38C above the early 1900s

Year to June 2021

min .95C above the early 1900s

max 1.16C above the early 1900s

Year to July 2021

min 1.04C above the early 1900s

max 1.09C above the early 1900s

Year to August 2021

min 1.04C above the early 1900s

max 1.13C above the early 1900s

Year to September 2021

min .78C above the early 1900s

max 1.04C above the early 1900s

Year to October 2021

min .77C above the early 1900s

max .95C above the early 1900s

Year to November 2021

min .70C above the early 1900s

max .89C above the early 1900s

Year to December 2021

min .74C above the early 1900s

max .97C above the early 1900s

Year to January 2022

min .71C above the early 1900s

max .96C above the early 1900s

Year to February 2022

min .75C above the early 1900s

max 1.13C above the early 1900s

Year to March 2022

min .77C above the early 1900s

max 1.15C above the early 1900s

Year to April 2022

min .75C above the early 1900s

max 1.03C above the early 1900s

Year to May 2022

min .69C above the early 1900s

max 1.04C above the early 1900s

Year to June 2022

min .78C above the early 1900s

max 1.17C above the early 1900s

Year to July 2022

min .62C above the early 1900s

max 1.23C above the early 1900s

The data shows averaged annual temperature across WA rose sharply from November 2009, the month the BOM software bug was corrected to adjust August 2009 average temperatures up by about half a degree. The above data is charted below:

bom database bug graph

BOM monthly data is available for all WA recording locations with historic averages which can be used to verify the trend I calculate from 32 locations compared to 1900 baseline temperatures.

The sharp upward trend compared with the 1900 average is reflected in BOM ACORN data below (BOM website source) which shows the overall WA mean temperature jumped by almost 1 degree C beginning in the spring of 2009 between August and November, broken into seasons to give some averaged time perspective.

Jul 2008 - 14.39C - 0.42C above average
Aug 2008 - 16.52C - 0.64C below average
Sep 2008 - 20.99C - 1.3C above average
Oct 2008 - 24.57C - 1.43C above average
Nov 2008 - 24.6C - 1.3C below average
Dec 2008 - 27.4C - .5C below average
Jan 2009 - 29.7C - 1C above average
Feb 2009 - 28.7C - .6C above average
Mar 2009 - 26.7C - 0.1C above average
Apr 2009 - 23.8C - 0.6C above average
May 2009 - 18.7C - 0.2C below average
Jun 2009 - 16.2C - 0.3C above average
Jul 2009 - 15.6C - 0.6C above average
Aug 2009 - 18.9C - 1.7C above average
Sep 2009 - 20.0C - 0.3C above average
Oct 2009 - 24.3C - 1.2C above average
Nov 2009 - 27.2C - 1.3C above average
Dec 2009 - 29C - 1C above average
Jan 2010 - 29.9C - 1.2C above average
Feb 2010 - 29.8C - 1.7C above average
Mar 2010 - 27.6C - 1C above average
Apr 2010 - 25.0C - 1.8C above average
May 2010 - 19.4C - 0.5C above average
Jun 2010 - 16.6C - 0.7C above average
Jul 2010 - 15.3C - 0.3C above average
Aug 2010 - 16.6C - 0.1C above average
Sep 2010 - 19C - 0.7C below average
Oct 2010 - 23.1C - long-term average
Nov 2010 - 26.6C - 0.7C above average
Dec 2010 - 27.9C - long-term average
Jan 2011 - 29.7C - 1C above average
Feb 2011 - 27.9C - 0.9C below average
Mar 2011 - 25.3C - 1.3C below average
Apr 2011 - 23.1C - 0.1C below average
May 2011 - 18.0C - 0.9C below average
Jun 2011 - 15.5C - 0.4C below average
Jul 2011 - 15.9C - 1C above average
Aug 2011 - 17.6C - 1.1C above average
Sep 2011 - 19.6C - 0.1C above average
Oct 2011 - 23.4C - 0.2C above average
Nov 2011 - 25.3C - 0.6C below average
Dec 2011 - 27.9C - 0.1C below average
Jan 2012 - 27.8C - 0.9C below average
Feb 2012 - 27.9C - 0.2C below average
Mar 2012 - 25.4C - 1.2C below average
Apr 2012 - 23.2C - long-term average
May 2012 - 18.8C - 0.1C below average
Jun 2012 - 15.8C - 0.1C below average
Jul 2012 - 14.3C - 0.7C below average
Aug 2012 - 17.7C - 1.1C above average
Sep 2012 - 21.2C - 1.5C above average
Oct 2012 - 24.8C - 1.7C above average
Nov 2012 - 26.7C - 0.8C above average

Note: the ACORN-SAT dataset is being used by the BoM for temperature area averages from December 2012 onwards. For this reason, all averages tabulated above are from a different set of weather stations and in many cases their mean temperatures bear no relationship to the mean temperatures listed below.

Dec 2012 - 28.5C - 0.60C above average
Jan 2013 - 30.1C - 1.20C above average
Feb 2013 - 28.7C - 0.62C above average
Mar 2013 - 26.6C - 0.02C above average
Apr 2013 - 25.2C - 1.96C above average
May 2013 - 19.8C - 0.86C above average
Jun 2013 - 15.5C - 0.43C below average
Jul 2013 - 15.6C - 0.61C above average
Aug 2013 - 18.1C - 1.56C above average
Sep 2013 - 21.1C - 1.37C above average
Oct 2013 - 24.9C - 1.77C above average
Nov 2013 - 26.8C - 0.90C above average
Dec 2013 - 28.2C - 0.32C above average
Jan 2014 - 28.9C - 0.16C above average
Feb 2014 - 27.6C - 0.47C below average
Mar 2014 - 27.6C - 1.03C above average
Apr 2014 - 23.7C - 0.50C above average
May 2014 - 20.3C - 1.38C above average
Jun 2014 - 15.9C - 0.05C below average
Jul 2014 - 15.2C - 0.21C above average
Aug 2014 - 17.7C - 1.18C above average
Sep 2014 - 21.7C - 1.97C above average
Oct 2014 - 25.5C - 2.45C above average
Nov 2014 - 26.9C - 1.05C above average
Dec 2014 - 28.6C - 0.69C above average
Jan 2015 - 29.3C - 0.63C above average
Feb 2015 - 30.4C - 2.30C above average
Mar 2015 - 26.7C - 0.06C above average
Apr 2015 - 22.2C - 1.04C below average
May 2015 - 18.2C - 0.68C below average
Jun 2015 - 17.5C - 1.59C above average
Jul 2015 - 15.9C - 0.91C above average
Aug 2015 - 17.6C - 1.10C above average
Sep 2015 - 20.4C - 0.72C above average
Oct 2015 - 26.4C - 3.28C above average
Nov 2015 - 27.7C - 1.78C above average
Dec 2015 - 28.7C - 0.82C above average
Jan 2016 - 28.9C - 0.17C above average
Feb 2016 - 28.6C - 0.46C above average
Mar 2016 - 27.9C - 1.34C above average
Apr 2016 - 24.8C - 1.60C above average
May 2016 - 20.0C - 1.11C above average
Jun 2016 - 16.8C - 0.88C above average
July 201 - 17.2C - 0.72C above average
Aug 2016 - 16.8C - 0.28C above average
Sept 201 - 19.1C - 0.60C below average
Oct 2016 - 23.4C - 0.33C above average
Nov 2016 - 26.9C - 1.02C above average
Dec 2016 - 27.9C - 0.0C average
Jan 2017 - 28.3 - 0.36C below average
Feb 2017 - 27.3C - 0.84C below average
Mar 2017 - 27.2C - 0.57C above average
Apr 2017 - 23.1 - 0.09C below average
May 2017 - 19.4 - 0.48C above average
Jun 2017 - 16.6C - 0.72C above average
Jul 2017 - 16.3C - 1.35C above average
Aug 2017 - 17.9C - 1.36C above average
Sep 2017 - 20.7C - 0.98C above average
Oct 2017 - 24.4C - 1.33C above average
Nov 2017 - 26.9C - 1.05C above average
Dec 2017 - 28.5C - 0.63C above average
Jan 2018 - 23.4C - 0.16C above average
Feb 2018 - 27.4C - 0.66C below average
Mar 2018 - 27.8C - 1.24C above average
Apr 2018 - 25.3C - 2.09C above average
May 2018 - 19.4C - 0.47C above average
Jun 2018 - 16.4C - 0.46C above average
Jul 2018 - 16.4C - 1.39C above average
Aug 2018 - 16.0C - 0.46C below average
Sep 2018 - 20.5C - 0.78C above average
Oct 2018 - 24.5C - 1.35C above average
Nov 2018 - 26.4C - 0.52C above average
Dec 2018 - 29.4C - 1.53C above average
Jan 2019 - 30.3C - 1.59C above average
Feb 2019 - 30.1C - 2.05C above average
Mar 2019 - 28.1C - 2.28C above average
Apr 2019 - 24.6C - 1.30C above average
May 2019 - 19.4C - 0.46C above average
Jun 2019 - 16.2C - 0.30C above average
Jul 2019 - 16.6C - 1.59C above average
Aug 2019 - 17.4C - 0.88C above average
Sept 2019 - 21.3C - 1.64C above average
Oct 2019 - 25.9C - 2.79C above average
Nov 2019 - 27.7C - 1.81C above average
Dec 2019 - 31.3C - 3.35C above average
Jan 2020 - 29.1C - 0.41C above average
Feb 2020 - 29.3C - 1.17C above average
Mar 2019 - 27.8C - 1.23C above average
Apr 2020 - 25.6C - 2.39C above average
May 2020 - 18.8C - 0.14C above average
Jun 2020 - 17.4C - 1.50C above average
Jul 2020 - 16.5C - 1.54C above average
Aug 2020 - 18.3C - 1.75C above average
Sep 2020 - 22.1C - 2.37C above average
Oct 2020 - 24.3C - 1.22C above average
Nov 2020 - 27.5C - 1.59C above average
Dec 2020 - 27.7C - 0.15C below average
Jan 2021 - 28.8C - 0.13C above average
Feb 2021 - 27.4C - 0.71C below average
Mar 2021 - 27.7C - 0.10C above average
Apr 2021 - 24.1C - 0.87C above average
May 2021 - 19.9C - 1.05C above average
Jun 2021 - 15.5C - 0.37C below average
Jul 2021 - 16.6C - 1.60C above average
Aug 2021 - 17.7C - 1.23C above average
Sep 2021 - 20.3C - 0.58C above average
Oct 2021 - 23.2C - 0.06C above average
Nov 2021 - 25.1C - 0.85C below average
Dec 2021 - 29.6C - 1.70C above average
Jan 2022 - 29.6C - 0.86C above average
Feb 2022 - 28.9C - 0.81C above average
Mar 22 - 28.2C - 1.59C above average
Apr 2022 - 24.2C - 1.03C above average
May 2022 - 20.0C - 1.09C above average
June 2022 - 16.8C - 0.94C above average
July 2022 - 15.4C - 0.39C above average


The statewide data above suggests temperatures in the 12 months to June 2022 were 1.02C above the 1961-90 average.

The BOM explains its baseline for the above anomalies thus: The climatological averages shown in the text and tables are generally long-term means based on observations from all available years of record, which vary widely from site to site. They are not shown for sites with less than 30 years of record, as they cannot then be calculated reliably. Climatological extremes are generally taken from available observations from all available years of record. The number of years can vary substantially from site to site.

The BOM also compares temperatures with the baseline average of 22.5C from 1961 to 1990. The BoM's portrayal of WA's temperature history is not static. The animation below shows the difference between the anomaly charts published in 2010 and 2013, the ACORN dataset of 2012 a probable reason for the early years cooling and temperatures warming since about 1930:


historic temperature anomalies wa

The bureau replaced the ACORN 1 temperature dataset of 2012 with a revised ACORN 2 dataset in late 2018, increasing Australia's per decade rate of warming by 23% (see analysis). In Western Australia, this cooled the 1961-90 anomaly baseline mean temperature at all 25 WA network stations from 20.44C in ACORN 1 to 20.15C in ACORN 2. The effect of this 0.29C difference (and further homogenised cooling of temperatures before 1961) can be seen in the animation below:


acorn temperature anomalies wa


Top of page


Bookmark and Share

This website produced by Scribeworks 2008-2022

Back To Top