The last two mornings have seen the mercury plummet to bone-numbing thresholds in Tasmania, with some places seeing their coldest nights in at least a decade. A high pressure system generating clear skies and light winds has combined with a cold air mass over the state to cause the very cold nights. For many places, Tuesday morning was the coldest. Liawanee on the Central Plateau dipped to an arctic -12.1 degrees, barely a degree off the Tasmanian all-time record, and the coldest recorded in its 12 year history. Ross chilled to -6.5 degrees, its coldest night in more than five years, while Launceston hasn't seen a colder July night in 16 years after dropping to -3.1 degrees. For other places, this morning was the chillier. Ouse reached a freezing -5.4 degrees, its coldest July night in 13 years, while Hobart Airport saw its coldest night of the year, dropping to 0.3 degrees. Fingal had a frosty minus six degrees for the second morning in a row, its coldest pair of July nights in almost a decade. The freezing nights and mornings will come to an end from tonight, with minimum temperatures set to rise gradually throughout the week as cloud cover increases over the state. Hobart is expected to dip to four degrees tomorrow, but by the start of next week it should only fall to eight degrees, well above the July average. Even the central parts of the state should warm into positive figures by the end of this week. The increased cloud will eventually amount to rain, with some good totals possible over the weekend, particularly in the north.