Man-made climate change is behind Australia's warmest October on record in 2015, a month in which Tasmania had record low rainfall while South Australia sweltered, an international report has found.
An annual report released on Thursday by the National Oceanic and Atmospheric Administration found climate change was a factor, however small or large, in 24 of 30 strange weather events worldwide last year.
They include 11 cases of high heat, as well as unusual winter sunshine in the United Kingdom, Alaskan wildfires and odd "sunny day" flooding in Miami.
The study documented climate change-caused weather in Alaska, Washington state, the southeastern United States, Canada, Europe, Australia, China, Japan, Indonesia, Sri Lanka, the western north Pacific cyclone region, India, Pakistan, Egypt, Ethiopia and southern Africa.
It found warming from CO2 contributed roughly one degree celsius to the extreme heat across Australia in 2015.
Other factors include a strong El Nino, a climate cycle in the Pacific Ocean with a global impact on weather patterns.
Tasmania experienced its driest October on record, which impacted agriculture as well as hydroelectric power generation. It also pre-conditioned the landscape for major bushfires the following summer.
The unseasonably warm weather over South Australia led to an early start to the bushfire season and caused significant crop losses across one of the country's most important agricultural regions, the Murray-Darling basin, the report said.
Using regional climate model simulations, scientists identified human climate change to have had a "substantial influence" on SA's extreme heat in October.
"El nino also contributed to the heat but its relative influence was much weaker," the report said.