Parts of New South Wales endured the coldest August morning in 12 years as fog and frost descended on the state. The Central West Slopes and Plains saw their lowest August temperatures since 2000 this morning. Trangie and Condobolin Airport cooled to -4 degrees, which was eight and seven degrees below average respectively. Clear skies and light winds last night combined with lingering cold air, following days of persistent southerly winds. This set up allowed heat to radiate away from the surface during the night, providing the ideal conditions for the mercury to plummet this morning. At one stage, the Northern Tablelands were colder than the Snowy Mountains this morning. Glenn Innes cooled to an icy -9 degrees shortly before 6am, eight below average and the coldest August morning in four years. Fog and frost became prominent features as temperatures dropped around the state. Roads were closed at Black Mountain near Armidale due to ice. Further south, visibility was reduced to 200 metres in Orange in thick fog, where the temperature reached a low of -4. Canberra reached a numbing low of -7 degrees, which was the state capital's lowest temperature in just over a year and eight below the monthly average. Closer to the coast, Sydney escaped with a low of seven degrees, which was only two below average thanks to the moderating influence of the Tasman Sea. Friday morning will be another cold one for northern and eastern New South Wales, although it won't be as cold as this morning. Temperatures will be a few degrees warmer across the state due to an increase in cloud cover, although frost and fog are again a risk on the northern slopes and ranges.