Tomorrow will be partly cloudy with a shower or two and a chance of thunderstorms and the temperature will drop to a cool 23 degrees.

Saturday will be even cooler at 21 degrees with a few showers from late morning and a chance of thunderstorms during the afternoon and evening.

While the temperature will rise to 24 degrees on Sunday, the showers will continue with a possible thunderstorm developing in the evening.

The Bureau of Meteorology's Richard Carlyon said the thunderstorms were a result of humidity moving through from the eastern parts of Victoria and along with an upper level trough would bring the storms to central Victoria.

The cool conditions, humidity plus thunderstorms was a rare occurrence for summer in Bendigo, Mr Carlyon said.

"It happens every so often but usually when we have storms in the summer, it's in the mid to high 30s when there's more humidity."

While rain is predicted throughout the weekend across the state, Mr Carlyon said the rainfall in Bendigo would be "moderate".

Mr Carlyon said the drop in temperature would be caused by the increased cloud cover throughout the weekend.