It was not uncommon for fires to be started by lightning strikes, especially with such dry conditions, he said.
North Canterbury was in a restrictive fire ban, but both sites were near Marlborough which was in a total fire ban.
"The area is mainly covered in scrub, we will monitor it overnight and clean up tomorrow morning.
"It hasn't been that windy tonight, that has been very fortunate."
Both of the fires were in isolated high-country areas and were not a threat to any buildings.
Fire and Emergency New Zealand was also assessing resources needed for both fires and across the region tomorrow, given the weather conditions.