Adelaide earned the title of the hottest city on the planet yesterday as temperature records tumbled across SA and the CBD sweltered through its hottest ever day of 46.6C.

The mercury reached 46.6C at the city’s West Tce station at 3.36pm, breaking the previous record of 46.1C, which was set on January 12, 1939.

Twenty-eight suburbs and towns surpassed historic maximums, including Port Augusta, where the barometer reached a scorching 49.5C – the fourth-highest temperature recorded in SA – and Tarcoola, which broke its record for the second time in nine days, with 49.1C.

Vic and SA could be plunged into darkness Vic and SA could be plunged into darkness

About 25,000 properties were without power at the peak of the outage on Thursday afternoon, as Adelaide’s record-breaking heat took a toll on energy infrastructure.

Power was gradually restored from about 11pm on Thursday evening and into the early hours of Friday morning.

media_camera Forecast weather for Adelaide this week.

Images: How we took on a brutal day media_camera Brompton's Hawker Street Cafe manager Michael Tomljenovic serving iced coffee to his customers before shutting up amid the intense heat. Picture: AAP image/Emma Brasier 1 of 21 media_camera Man hydrating himself in the city. Picture: Roy VanDerVegt/AAP 2 of 21 media_camera Renato Lovisa of Italy and Natasha Romano of Newton find the best way to cool off in a tidal pool under a beach umbrella at Glenelg. Picture. ROY VANDERVEGT 3 of 21 media_camera Jumping off the Glenelg Beach jetty. Picture: AAP Image/Kelly Barnes 4 of 21 nav_small_close Want to see more?( 17 more photos in collection )Continue to full gallery nav_small_left nav_small_right

South Australia’s fleet of diesel generators were fired up for the first time, amid tight power supplies here and in Victoria.

Bureau of Meteorology senior forecaster Brett Gage described SA’s record-breaking day as “amazing” and said it was likely to be the hottest ever on average across the state.

He said temperatures were anywhere between 10C and 22C above average for this time of year.

Other notable milestones for exceeding previous temperature records by more than 1.5C were Port Pirie (48.6C), Roseworthy (48.3C), Port Lincoln (48.3C), Edithburgh (47.9C), Kadina (47.9C), Kent Town (47.7C), Hindmarsh Island (46.8C), Stenhouse Bay (46.7C), Noarlunga (46.2C), Nuriootpa (46C) and Adelaide Airport (45.8C). Mt Lofty recorded its first day above 40C when the temperature reached 41.1C at 1.59pm. Its previous hottest day was 37.9C on January 28 last year.

A mild cool change moved across Adelaide on Thursday night. The temperature didn’t drop below 30C until after midnight, and by 5.50am on Friday it was 23.7C. Today is set to

reach 31C, while the high 20s and low 30s are forecast for the Australia Day long weekend.

The extreme heat led to 65 people presenting at hospital emergency departments across the state with heat-related issues in the 48 hours to 8am on Thursday.

Hospital staff on Thursday offered to reschedule outpatient appointments for elderly patients who would have had to travel during the peak of the heatwave.

The South Australian Ambulance Service reported 39 heat-related call-outs between 8am and 2pm. Of those, 16 patients were taken to hospital.

An SAAS spokeswoman said that, while its workload was high because of the increasing number of call-outs, staff were coping.

The soaring temperatures caused issues for Adelaide Metro ticket machines, which were damaged in the sun at exposed tram and train stations.

The machines were left temporarily out of order.

The heat also caused tram delays, which started between the Entertainment Centre and the Botanic Garden and spread to the rest of the system just before afternoon peak-hour.

Trains on the Seaford and Tonsley lines also experienced delays due to power issues.

While some businesses struggled in the heat, one northern suburbs pub was conducting a roaring trade after linking their beer prices with the temperature.

The Red Lion Hotel, at Elizabeth North, offered free beer when the temperature exceeded 45C.

Exhausted publican Stephen Firth said he estimated almost 200 customers had come through the door and drained about 15 kegs of beer throughout the day.

“The free beers lasted a lot longer than we thought they would,” he said.

“But there were a lot of $1 beers as well which kept customers pretty happy.”

Staff and management of the pub are now discussing the future of the “beer-o-meter”.

Today’s relatively cool weather will continue throughout the day with partly cloudy conditions.

A senior Bureau of Meteorology forecaster says the cool change took a while to establish, and there could even be a scatter of rain.

“We’ve got a 20 per cent chance of a shower on the forecast; there’s been some very weak echoes moving past on our radar overnight,” he said.

“And they likely continue during the day, but there is not going to be enough to be any sort of significant rainfall, unfortunately.”

Towns further north in the state must, unfortunately, endure another hot day but it’s still cooler than Thursday. 37C is forecast in Port Augusta and 43C in Hawker.

Whyalla, however, will enjoy a 31C maximum and further down the Eyre Peninsula, Port Lincoln is set for a 28C maximum with showers.

Looking ahead, the relatively cool temperatures are expected to continue with a maximum 29C is forecast on Saturday and 27C on Sunday before heading into the 30s again next week.

— with Michelle Etheridge