Two people died on June 1 in a crash on State Highway 14, near the intersection of Otuhi Rd, Wheki Valley, west of Whangārei.
And on May 30, two people died in a crash involving two trucks on SH10 at Kaingaroa, in the Far North.
The collision occurred at the intersection with Pukewhai Rd, midway between Awanui and Taipā.
One person was found dead at the scene and another was taken to hospital in a critical condition and later died.
Police said inquiries into the circumstances of all three crashes were underway, and they could not release further details.
Police have yet to release the names of any of the five people who died.
The deaths bring Northland’s road toll for the year to 20, compared with 12 at the same stage last year.