Canberra has experienced its coldest run of temperatures in 36 years, with the mercury dropping below zero for the seventh time in a row.

The minimum temperatures have averaged minus five so far this month.

Meteorologist Ryan White says the warmest night this July so far has been 0.7 degrees.

"The last eight nights in a row we've had it pretty much at the minus five degree mark as an average, so it is quite incredible," said Mr White.

Today the mercury dropped to -4.8 degrees shortly before 7:00am AEDT.

But Mr White says the spell of cold nights is nowhere near the record.

"The record I believe of consecutive sub zero nights was 23," he said.