You'd normally expect the hottest location in Australia on a summer afternoon to be somewhere in Central Australia or the northwest corner of WA, rather than on Australia's southern coastline.

Indeed it was around this time last year that Onslow in WA's Pilbara region recorded 50.7°C, equalling Australia's previous all-time hottest reading at Oodnadatta in outback SA.

But if the right weather set-up occurs, the coastline around the Great Australian Bight can be hotter than anywhere else in the country, and that’s what's happening this Friday afternoon.

As you can see on the chart below which shows live temps at 2:20 pm AEDT (1:40 pm in SA), it was 44°C in Ceduna, the coastal town of 3,500 residents on the far northwest edge of the Eyre Peninsula. Nowhere else was close. A little later in the afternoon, the mercury reached 44.6°C.

• Today's reading of 44.6°C is 16 degrees above Ceduna's January average max, and its first 40-degree day this year.
• Nearby, Wudinna reached 43.6°C, 10 above average; and Minnipa 43.5°C, its hottest day in two years.

Interestingly, this part of the country has seen some of the nation's hottest temps ever recorded.

• Nullarbor (a tiny SA spot near the WA border) and Eucla (a WA town just over the SA border) have both come perilously close to 50°C in the past, with temps in the top 10 highest ever recorded for Australia.
• Ceduna's record temp is 48.9°C, which is pretty remarkable for a weather station so close to the coast it probably gets salt spray.

Why is this region so hot?

Simply speaking, hot air masses always build up over the interior of the country in summer, but on occasion with northerly or northwesterly winds, temps will be even hotter near the coast due to the lower elevation of coastal districts.

Most parts of Central Australia are at least a few hundred metres above sea level. If they weren't, it's likely that we'd see many more days in excess of 50°C in the nation's red heart.

Meanwhile as you can see on the heat map below, the heat is biting in the Great Australian Bight this Friday afternoon, and it’ll move east too in the next day or so.

Adelaide is sweating through an afternoon in the high 30s and a very uncomfortable night lies ahead with minimum temps in the mid 20s before cooler air moves in on Saturday.

Melbourne will feel the heat with a top of 35°C on Saturday, though it appears likely that a dry southerly change will move through to cool things down before the Australian Open women’s final starts at 7:30 pm.

Enjoy your weekend.