Mr Williams sent messages to Mr Key as late as 3.30am and also texted other Cabinet ministers.
Mr Key has described the texts as aggressive and obnoxious.
The mayor has disputed that and says he just makes his points. He says the late messages are because he works at night.
"Politicians need to have thick skins and I certainly get plenty of pointed messages, texts and emails on different subjects but that goes with the territory."
Mr Williams said Mr Key could have raised the issue with him rather than speak to the media.
Mr Key told Breakfast on TV One that Mr Williams tended to "rant and rave" in long messages largely about the supercity changes in Auckland.
"There's been a few in the last six or seven months and they come at all sorts of weird times of the day and night, generally actually not the day," he said.
"The problem I have is I have to leave my phone on at night... just in case there's a serious issue and someone needs me, and occasionally I have been woken up."
Mr Key said the texts were often quite lengthy.
"Once you start getting through the first bit it's turn off material."
He had not bothered to complain.
"I'm not going to complain about text messages. I've got a pretty thick skin, I just don't spend any time worrying about it."
Mr Key told Newstalk ZB that he did not think the texts were worthy of a reply and the points made in them were "not overly" sensible.
"I don't mind if people communicate with me, there's a better way to get my attention than to text me at 3 in the morning I would have thought."
Asked he wanted an apology, he said: "No I don't care about that."
Mr Williams is known for his late night contacts.
In October he emailed his mayoral predecessor George Wood about 11.30pm describing him as a "buffoon" and a "disgruntled, failed has-been", as well as leaving abusive messages on his voicemail.
Cabinet Minister Wayne Mapp said he had received messages from him at unusual hours.
