Bureau of Meteorology figures show autumn has been one of the warmest on record for the Bathurst region with monthly average maximum temperatures for March, April and May above the long-term average.

April was particularly unseasonal with an average maximum of 25.1 degrees Celsius compared to the long-term average of just 20.9.

But with the first day of winter to come on Friday, residents should prepare to rug up against the cold.

The bureau says we can expect a top of just 11 degrees on Wednesday with a chance of snow south of the city.

A small patch of snowfall is forecast on high country around Shooters Hill, near Oberon, where the temperature is expected to get just seven degrees.

Bathurst can then expect a top of 11 again on Thursday and 12 on Friday for the first day of winter.

There is only a slight chance of rain this week, continuing a dry spell that has seen just 3.8mm of rain recorded at the official weather station at Bathurst Airport for all of May.

The temperature dropped to an overnight low of -0.6 degrees in Bathurst this morning with the bureau forecasting a sunny afternoon and maximum of 18.