Severe frosts in South Australia are rare enough, now with unusual cold in the tropics too.

The far north and far south of Australia both registered their lowest temperature in more than five years on Tuesday morning, according to Weatherzone.

In Tasmania, Hobart’s -0.2 degrees Celsius shortly before 5am on Tuesday was the city’s lowest temperature since 2013. It was also its third coldest morning in the last 20 years.

In the tropical north, Darwin Airport dipped to 12.7C just before 4:30am on Tuesday, which was their lowest temperature in eight years. Just to the ease of Darwin, Middle Point’s 4.8C was its lowest temperature since at least 2001.

While cold mornings are common in Australia during winter, the chill on Tuesday morning was given a boost by dry air in both Tasmania and the north. Dry air allows much more cooling of the ground because it prevents the formation of mist or dew, both of which act as insulation for the surface.

Darwin Airport’s coldest morning on record is 10.4C during July 1942, while Hobart’s lowest was minus 2.8C, from July 1981 and June 1972.

South Australia has seen temperatures plummet well below zero, severely damaging soft crops. The Bureau of Meteorology said Monday’s low of -5.7C at Renmark, in the state’s Riverland, was the equal-second lowest temperature on record for the town.

Meteorologist Matthew Bass said it was the region’s sixth consecutive day below zero.

“Those sort of temperatures are not what we see very frequently in South Australia … It’s a very significant, severe low temperature.”

Air from the Antarctic has been drawn over Australia by a series of active weather systems and these events are a legacy of that source area. Persistent high pressure has kept the air in place and the skies mostly clear.