Cr Weatherall (64) told the Otago Daily Times he was scheduled to have a colectomy at Mercy Hospital on Wednesday, and would spend the next few weeks recovering in hospital and at home.
The colectomy involved the removal of the growth, his appendix and part of his lower bowel.
That meant Cr Weatherall would miss upcoming council committee meetings. He had passed his duties as chairman of the council's resource consent hearings committee to colleague Cr Andrew Noone.
Cr Weatherall hoped to recover sufficiently to attend May's draft annual and long-term plan budget hearings, but that would depend on whether he felt he could handle the long sessions, he said.
Dealing with his health scare "hasn't been easy", but Cr Weatherall had support from wife Ann and others, including Mayor Dave Cull.
"The surgeon has indicated to me that it's a cancerous-type growth.
"Whether it's malignant or [benign], I don't know. We won't know that until after the operation."
However, Cr Weatherall was determined to bounce back quickly.
"The surgeon's telling me four to six weeks [recovery time] and I'm telling him two to four.
"I'm extremely positive. I'm just lucky that I'm in the hands of a very good surgeon. There's a lot more people that are worse off than I am.
"The first goal for me is to sit up in the hospital bed, hopefully, next Friday night and watch the Highlanders beat the Blues."
• News of Cr Weatherall's health scare came after Cr Paul Hudson was also forced to withdraw from some council duties last month, as he struggled with continuing complications after fracturing his shoulder in 11 places last year.
Cr Hudson was understood to be facing further shoulder surgery after being readmitted to Dunedin Hospital for a few days last month, but was continuing with light council duties in the meantime.
Cr Hudson has not returned ODT calls.
