Onslow, a coastal town in Western Australia's Pilbara region with a population of around 900, holds half of a significant Australian heat record – equalling Australia's highest recorded temperature when the mercury reached a searing 50.7°C in January 2022.

On average, Onslow is not quite as hot as several other WA towns such as Marble Bar, which sits 200 km inland from the Pilbara coast, but it's still plenty hot enough, and the heat in October 2023 was quite remarkable.

In October 2023, Onslow's average maximum was a whopping 5.7°C above the long-term monthly average from 1943-2023.

• Onslow's long-term average max in Oct is 32.9°C
• Onslow's average max in Oct 2023 was 38.6°C

The remarkable anomaly of almost six degrees was caused by higher-than-normal air pressure which lingered over central Australia during October due to the active El Niño and positive IOD.

This directed persistent southeasterly winds to the Pilbara coast, pushing hot desert air to the coast and delaying sea breezes most days.

Image: Another beautiful scorching day in Paradise. iStock.

Meanwhile across Australia, October average maximum temperatures were much warmer than usual in almost all areas, with seven of the eight capital cities recording above-average max temps.

The list below shows how far each capital city’s October 2023 max temps were above or below the long-term monthly average:

Sydney +3.5°C (3rd-hottest Oct on record for max temps)

Perth +2.9°C (2nd-hottest Oct on record for max temps)

Darwin +1.3°C

Hobart +1°C

Canberra +0.7°C

Brisbane +0.5°C

Adelaide +0.1°C

Melbourne -0.5°C

If you're in Melbourne and you thought October was a little chilly overall, even by local standards, you're right.