A 55-year-old woman is dead and a truck driver is in a serious condition after a head-on collision between a car and truck near Lake Rotokawau.

Emergency services were called to the crash on State Highway 30 just west of the Lake Rotokawau Road intersection at Tikitere at 11.15am today.

The truck involved in the crash.

The woman who died in the crash was the driver and sole occupant of the Honda CRV.

Police say a truck crossed the centre line into the path of the Honda.

SH30 is now open after being closed for several hours to allow the serious crash unit to assess the scene.

Police say they are investigating if a localised hail storm at the scene contributed to the crash.

The Honda CRV.

Police say hail may have be a factor in the accident.