Following a period of prolonged, above average heat over most of the eastern parts of Australia, a strong cold front currently moving off the eastern seaboard should bring significant cooling in its wake.

On Sunday morning, most of inland NSW west of the Great Dividing Range should see minimum temperatures well below 10 degrees, finally making it feel like autumn. In fact, it should be the coldest morning of the year over such a large portion of the country, with some locations along the slopes and tablelands probably seeing the first hint of frost.

Places like Canberra, Orange, Armidale are likely to cool to below 5 degrees, while frost and near-zero temperatures are possible for places like Cabramurra.

Cold air in the wake of a cold front can lag behind the actual airmass boundary that we understand to be and mark as the actual cold front. As is the case with the current system, and apart from the initial cool burst of air,  cold air being dragged up from the Southern Oceans will take a while to cover such a massive area of land, making Sunday the actual colder day for much of the state.

Early morning cooling will be enhanced further by skies clearing rapidly in the wake of the system, allowing for less heat to be trapped, as would be the case with partial or complete cloud cover.