AUSTRALIA SWEATED THROUGH its hottest month ever in January, with average temperatures exceeding 30C for the first time since records began in 1910.

Fruit cooked on trees, more than a million fish died and bushfires were a persistent threat as a powerful heat wave gripped the country.

It was a record-breaking month on several fronts with new landmarks reached for highest maximum, highest minimum and highest mean temperatures, according to a monthly climate report published by the Bureau of Meteorology.

“We saw heat wave conditions affect large parts of the country through most of the month, with records broken for both duration and also individual daily extremes,” said senior bureau climatologist Andrew Watkins.

The warming trend which has seen Australian temperatures increase by more than one degree in the last 100 years also contributed to the unusually warm conditions.

The month had at least five days that are among the 10 warmest ever, with national temperature highs surpassing 40C. 

The record smashing month comes hot on the heels of the hottest December on record.

South Australia experienced the most extreme heat with the mercury hitting 49.5C on 24 January.

Many places experienced record-long runs of consecutive hot days. Birdsville in Queensland had 10 consecutive days over 45C and Alice Springs Airport in Northern Territory had 16 days in a row above 42C.

Several other areas have experienced dozens of consecutive days with temperatures above 40C. 

Authorities said the heatwave contributed to the deaths of more than a million fish in the Murray-Darling river system.

It also led to the death of numerous more wild animals including more than 90 wild horses.