The city will wake up to an overnight low of minus-1 on Wednesday morning, followed by a top of 21 degrees - almost two degrees above average.

According to Bureau of Meteorology statistics dating back to 1969, Cessnock's average maximum temperature for August is 19.4 degrees.

Tops above 20 degrees are expected every day over the next week, peaking at 26 degrees on Sunday.

In contrast, another subzero night is predicted for Thursday morning, with lows of two to eight degrees for the rest of the week.

This month's average minimum of 2.7 degrees is almost two degrees below Cessnock's long-term average low of 4.5 degrees.

See weatherzone.com.au for the updated forecast.