Scorching in the north, pretty darn chilly in the south: That's been the picture this Tuesday afternoon in South Australia.

At 3:10 pm local time as we were writing this story:

• Oodnadatta in the northern part of the state's North East Pastoral forecast district was sitting on a somewhat sizzling 43.5°C.
• Cape Jaffa, near Kingston in the state's Lower South East forecast district, was sitting on just 16.3°C.
• That was a difference of 27.2°C.

Oodnadatta actually reached 45°C shortly before 3 pm, but Cape Jaffa was a couple of degrees warmer at the time. So it's likely that the 27.2 degree difference between the hottest and coolest SA weather stations at 3:10 pm was close to the largest concurrent gap of the day.

That's a very large gap by South Australian standards.

Other recent large temperature variations

Here at Weatherzone, we love a temperature contrast story.

• Recently, we wrote about a 50-degree difference between the nation's hottest and coldest temperatures within a 24-hour period. For the record, the locations were Fitzroy Crossing, WA, with 43°C and Mt Hotham, Vic, with -7°C.
• We also wrote a story back in August about a 30-degree concurrent temperature difference in New South Wales.

While these were both noteworthy events, the large contrasts relied on mountain weather stations for the cold-temp readings – and temperatures almost always decrease with altitude.

What's remarkable about today's SA temperature contrasts is the similar altitudes of the two stations we've mentioned, with Oodnadatta sitting on 116 m above sea level, while Cape Jaffa is near sea level at just 17 m.

So why the large SA temperature gap?

As you can see from the pink blobs on this afternoon's map of live temperatures Australia-wide, heatwave conditions are currently affecting the northern parts of SA, southern parts of the NT, a large part of northern WA and even the southwest tip of Qld.

Meanwhile cool Southern Ocean air is licking the far south of SA. Adelaide is experiencing the effects of that cooler air, but to a much lesser degree than parts of SA lying further southeast. The SA capital peaked at 27.1°C just after 3 pm.

We of course know that southern parts of SA can experience extreme summer heat. Even Mt Gambier in the far southeast corner of the state has seen temps of 44°C or higher in each month of summer, with a record high of 45.9°C in the scorching summer of 2019/20.

But for today, the extreme heat is confined to the north of the state while it's jumper weather in the far southeast.

Unseasonably cool weather should persist in the state's southeast for the next week or so, with top temps even dropping by a degree or two in coming days.

A brief surge of heat is expected on Saturday, when Adelaide could reach the mid-30s, before max temps will plummet back into the low 20s again on Sunday and Monday.