Large swathes of NSW awoke to a frigid morning on Saturday with temperatures dropping three-to-six degrees below average.

Clear skies and light winds over much of NSW allowed for the daytime heat to escape, with overnight temperatures plunging well below the October average.

Cessnock cooled to 2.5 degrees, which is more than seven below average and it hasn't been this cold in October since 2014. Elsewhere, Bourke dropped to 7.2 and Wellington to 1.6 degrees, 6.4 and 7.2 degrees below average respectively. Armidale dropped below zero for the second morning in a row. The last time they experienced back-to-back freezing mornings in October was 2016.

Sydney's western suburbs were mainly three-to-five degrees below average. Camden was the stand out, dropping to just three degrees, which is seven below average. Along the coast though the ocean helped to mitigate the cool conditions. The city itself dropped to 14.5 degrees, nearly a degree up on average.

Overall Sunday morning will be warmer with increased winds and cloud cover associated with a cold front and trough. This front though will bring a colder airmass with it though so areas will have a cold start to Sunday as well.