A truck driver has been winched to safety from his cabin as floodwaters engulfed the vehicle south-west of Broken Hill.

Rain has inundated outback NSW, closing highways from Queensland to South Australia.

The rescue helicopter arrived in the remote town of Yunta near Broken Hill.

One crew member was winched down, balancing on top of the cabin as the driver clung on.

He attached the harness and both were brought to safety.

The rescue happened yesterday afternoon on the South Australian border.

Roads have been closed across almost half of NSW, although for many it's not a curse but a blessing.

Orroroo Mayor Grant Chapman said the rain was "magic", with more than two thirds of the annual rain falling.

Mildura was lashed with almost 150 millimetres of rain in the 36-hour period to 9am today, flooding a major highway and triggering a barrage of calls for help to the State Emergency Service.