The Climate Council says Australia’s increasingly hot summers pose a serious threat to critical infrastructure, and has again called for the urgent uptake of renewable energy.

The call follows the ending of Australia’s most intense summer yet, with more than 205 temperature records broken in 90 days.

The highest summer temperatures were recorded in 66 locations nationwide, the most rainfall occurred in 89 places, and 50 locations reported a record number of days above 35 degrees.

Sydney had its hottest summer on record, with a mean temperature 2.8 degrees above average, while Brisbane’s mean temperature was 26.8 – 1.7 above average.

Canberra had its hottest daytime temperatures on record and passed 35 degrees on 18 days – more than the 12 days projected for 2030.

The council says the 2013/14 so-called “angry summer” cost the economy about $8 billion through absenteeism and reduced productivity.

“Escalating extreme weather is putting Australia’s ageing energy system under intense pressure,” it says. “Australia’s energy system is ageing, inefficient and polluting, and during the summer proved unable to cope with escalating extreme weather.”

The council says extreme heat and heatwaves will become more frequent and severe, putting the economy, electricity supply, health and ecosystems at risk.

“Protecting Australians from the impacts of summers with relentless extreme heat requires the uptake of cheap, clean and efficient renewable energy and the phasing-out of fossil fuels.

“Commissioning new fossil fuel – coal, oil and gas – projects is incompatible with limiting the dangerous impacts of climate change, such as the failure of critical infrastructure.”

The council says extreme fire weather is increasing in the southeast. During the summer’s most severe heatwaves, nearly 100 bushfires hit parts of NSW.

Above-average sea surface temperatures triggered a new bleaching outbreak on the Great Barrier Reef. This follows the worst mass-bleaching event in recorded history last year.