One is the loneliest number - and sometimes the coldest.
Melburnians have woken to a bone-numbing morning, the coldest morning in any month for more than 18 years, with the temperature in the city hovering at around one degree for an hour after 6am on Sunday.
The Bureau of Meteorology recorded a stinging one degree at 6.49am, falling further to 0.8 degrees at 7.26am, making it the coolest morning since August 5, 1997, when the temperature was a teeth-rattling 0.3 degrees.
Sunday morning was the coldest July morning since 1994. "The last time we had a zero in rounded figures in Melbourne was August 1997 ... and it's never happened since," said Bureau senior forecaster Scott Williams.
The reason? On a winter's night you need a blanket and last night Melbourne had no cloud cover to slide under. Last week's aggressive, extended stretch of cold (which involved three cold fronts sweeping through the city) left a parting gift: dry air. "We have now had a night with no cloud, no wind and with this dry air ... that's what's brought about this exceptionally cold morning."
Sunday was coldest in Ballarat, with the temperature dropping to minus 4.9 degrees. "Ballarat reached the same temperature as Mount Buller and Mount Hotham," Mr Williams said. "That's quite exceptional."
At Essendon Airport, temperatures dropped to minus 1.5 while in Rutherglen and Coldstream it was minus 4. But in the far west of the state, thin cloud cover prevented Horsham from dropping lower than 3 degrees and Hamilton recorded a low of just 4.8 degrees. 'We had some cloud lingering in the far west of the state that stopped frost occurring out there ... you can't quite wear a T-shirt with 3 degrees but it's a bit milder and it'd be about an average night for Horsham at this time of year."
Today is expected to be sunny with a top of 13. "It's going to be a lovely, sunny day," said Mr Williams. "It will not feel particularly cold this afternoon because there is hardly any wind."
Later in the week strong winds and mid-week showers are forecast but warmer nights are expected, with a Wednesday overnight forecast of a decent 11 degrees. "We are not going to get that really cold air mass," said Mr Williams. "So a milder week after this very, very chilly series of nights."