CANBERRA, April 11 (Xinhua) -- Residents of South Australia (SA) were warned on Wednesday to prepare for widespread blackouts and bushfires as an unseasonal heat wave continues.

Temperatures across the state were forecast to pass 34 degrees Celsius for the fourth day in a row on Wednesday, the state's most severe April heatwave since records began 132 years ago.

The Bureau of Meteorology (BOM) on Wednesday issued severe fire warnings for multiple regions, warning of winds of up to 50 kilometers per hour (kmph) in addition to the heatwave.

South Australia's Country Fire Service (CFS) issued a total fire ban for 10 of the state's 15 districts.

Rob Sandford, assistant chief CFS officer, said conditions across the state on Wednesday would be the worst ever experienced in April.

"People will be put at risk if fires start," he told News Corp Australia.

The state's electricity grid came under considerable strain on Tuesday night due to low wind farm generation and system maintenance.

The grid, which is made up of 50 percent renewable sources, ran at full capacity on Tuesday with the world's largest lithium ion battery, which was built by U.S. energy giant Tesla, supplementing it to prevent blackouts.

Dan van Holst Pellekaan, the state's new Energy Minister, said that the maintenance typically took place between the summer and winter months when demand was typically the lowest.

The Australian Energy Market Operator (AEMO) issued a supply shortage generation, noting the lack of reserve power.

"The contingency capacity ­reserve required is 600 megawatts (MW) -- the minimum reserve available is 376MW," the alert said.