It’s the peak of summer in the Southern Hemisphere, and this week historic heat waves have hit both Australia and South America.
On Thursday, January 13, one of the most iconic world weather records was tied when a ferocious heatwave in Western Australia sent the mercury soaring to 50.7 degrees Celsius (123.3°F) in the coastal city of Onslow.
This tied the previous all-time heat record for hottest temperature for the entire Southern Hemisphere, set on January 2, 1960, at Oodnadatta Airport in South Australia.
The heatwave over Western Australia built over the week, aided by sea surface temperatures approximately 2 degrees Celsius (3.6°F) above average, offshore winds, and subsiding upper-level air created by the landfall of Tropical Cyclone Tiffany over north-central Australia.
Three stations in Western Australia exceeded the 50 degrees Celsius mark on January 13. Before this week, the entire nation of Australia had recorded only four instances of temperatures of 50 degrees Celsius (122°F) or more, in records going back to 1910.
The heatwave continued on Friday, January 14, but with slightly less-scorching temperatures. Onslow was again the hottest major airport, topping out with a high of 48 degrees Celsius (118°F). The heatwave is expected to diminish in intensity over the weekend.
The new record will undergo review by the World Meteorological Organization (WMO) before it is certified as being official, perhaps a lengthy process. In an interview with the Washington Post, Randy Cerveny, who leads the World Meteorological Organization’s weather and climate extremes team, said, “Since the creation of the WMO World Archive of Weather and Climate Extremes in 2007, we have never had so many ongoing verification/evaluations as we currently do. We are seeing more frequent extremes in temperature. The climate that we have lived through over the past decades is changing and we must be aware of that — and realize those fundamental changes have consequences to our way of life.”