The Dunedin City Council this week decided the closure would start on May 1.
That followed the council being advised much of the museum was a "construction site" for the duration of its $35 million redevelopment and that some visitors had reacted negatively to seeing only the two small exhibitions offered this year, while the museum was almost all closed.
Museum authorities have emphasised that although the two shows will close, the museum's education, school holiday and other special programmes will continue.
Director Linda Wigley said large advisory banners were being planned, to be displayed outside the museum.
"We want to get across the enormity of the project," Ms Wigley said in an interview. A bigger, brighter and "more dynamic" museum would result, she said.
Museum visitor programmes webmaster Lynda McLea, who previously worked at the Otago Polytechnic, was employed in January, and would help develop a new website. Dunedin firm Areo had been developing an electronic kiosk - its location as yet undecided - to offer a virtual view of the museum's historic photographs.
Attendance figures tabled at yesterday's museum board meeting showed there had been 41,503 visits to the museum from July 1 last year to March 13 this year, down 15.5% on on the corresponding period the previous year.
