Welch confirmed the unofficial road toll now stands at 24 for the year, the process that follows a fatal crash would take a month before that figure was confirmed.
At the same time last year that number was 23.
Welch urged drivers to wear their seatbelts, drive sober, keep their phones away out of reach, stick to the posted speed limit and not to drive distracted.
Today, many motorists will be making a return journey to Auckland after enjoying a long weekend away thanks to Anniversary Day.
"January is always a high risk time to be driving because the volume of traffic on our roads is at its peak," Welch said.
The message was to travel safe, she said.
The first fatal crash on Sunday happened in the early morning in the country's far north.
A male died at the scene after his car left the road and collided with a tree in Kaitaia.
Emergency services were called to the crash on Bank St just after 6am.
A male then died in a two-vehicle crash near Lake Karapiro in Waikato.
The crash occurred on State Highway 29 shortly after 2pm.
A male and a female died and two more were injured in a crash in Mataura, Gore.
Police were called to scene about 5pm.
On Saturday, one person was killed and another was seriously injured in a car crash in Waikato.
The crash happened on State Highway 1 near Cambridge, about 6.20am.
According to the Ministry of Transport, the provisional number of road deaths for 2019 is 353 from 301 crashes.