Record average temperatures in autumn are clear evidence of climate change hitting Australia, a new report says.

Australia has experienced its hottest two years on record and high temperatures are set to continue through winter in a clear sign climate change is having an impact, a new report warns.

May 2012 to April 2014 was the hottest 24-month period ever recorded in Australia, but that is likely to be eclipsed by the two years between June 2012 and May 2014, according to the Climate Commission’s latest report, Abnormal Autumn.

“We have just had an abnormally warm autumn, off the back of another very hot ‘angry summer’,” Climate Council Professor Will Steffen said.

“The past two-year period has delivered the hottest average temperature we have ever recorded in Australia.

“Climate change is here, it’s happening, and Australians are already feeling its impact.”

The average temperature across Australia in April was 1.11C above the long-term average, the report says, citing Bureau of Meteorology figures.

The average minimum temperature was 1.31C above normal.

Unseasonable temperatures in the autumn “warm wave” set records, with Sydney, Adelaide and Melbourne setting benchmarks for the consecutive number of May days when the mercury reached 20C or higher.

In its report, the Climate Council says the abnormally warm weather in April and May “are part of a longer-term trend towards hotter conditions in the summer months and more warm spells in autumn and winter”.

It says each of the 12-month periods ending in January, February, March and April 2014 have been record warm periods for Australia, with May figures on track to also be a new high.

“Such records are consistent with the ongoing global and Australia-wide, multi-decadal trends towards a hotter climate,” the report says.

Meteorologists predict a high likelihood that Australia will experience an El Nino event – characterised by below-average rainfall in the east and south – in coming months.

The Climate Council says an El Nino could worsen the impacts of climate change, leading to hotter, drier weather.

The Climate Council is a crowd-funded, independent organisation created by the members of the former Climate Commission, which was axed by the coalition government when it came to power in 2013.