Clear skies and still winds have allowed the mercury to fall to a 43 year low in the nation's capital. A stubborn, slow moving high pressure system has given rise to a prolonged spell of cold mornings about southern parts of NSW. Inland parts of the state in particular, far removed from moderating sea breezes have endured brutally cold mornings leading to widespread frosts on multiple occasions. In the past seven days, Canberra has seen an average minimum temperature of -5.8 degrees, the coldest spell since 1971. Nearby, Cooma also felt their coolest three night spell since 2011 with an average minimum of -9.6 degrees. This is also the fourth coolest three night spell since records started in 1974. A cold front is set to sweep over southeastern parts of the nation this weekend bringing an end to the bitterly cold nights, although a large region of cold air should linger in its wake for the majority of next week. Initially, conditions over southeastern Australia will be fairly poor with cloud, wind and showers keeping day time temperatures down, however skies should clear by the start of the working week. Widespread frost with chilly mornings will become a high risk soon after as the next dominating ridge takes hold throughout next week.