The pin was pulled on the record attempt last week after he had to drive through the Desert Road because he felt the weather was too dangerous.
Newburn battled wind and rain, especially in the first half of the run and was not able to catch up.
"You can't beat the elements, it's as simple as that.
"But I'm pretty happy. If It'd been my own fault or my own mistakes that would've been different."
On reaching Bluff on Wednesday Newburn planned to turn straight around for the van trip home.
He was also using the run to raise money for Koru Care.
As of Thursday just over $2000 had been raised. People could continue to donate and he was hoping for a bit more.
Donations can be made at givealittle.co.nz/fundraiser/running4korucare
