On Saturday, it was replaced by a 2.5m high device which not only shows the temperature but also the time, along with the current UV reading.
The readings could be seen from 150m away, pharmacy owner David Budge said.
He decided to replace the thermometer when he discovered parts were becoming hard to find.
"This one's getting a little bit tired and the figures are not turning over properly - it quite often shows 77degC," he said.
Mr Budge worked with a digital designer and with the National Institute of Water and Atmospheric Research (Niwa), as he wanted to incorporate a UV reading. The unit, which cost almost $25,000, was built in Christchurch.
"It's a community project as far as I'm concerned, but I [the business] will certainly reap the benefits from having it here," he said, adding he did not think his clock would compete with Alexandra's "clock on the hill".
"I still think the clock on the hill is Alexandra's iconic clock."
The old thermometer was erected by the Alexandra Round Table about 25 years ago. Mr Budge has paid for the maintenance, and the power to operate it, since he took over the pharmacy 14 years ago.
Breen Construction installed the new thermometer on Saturday afternoon just in time for the longest night of the year.
The new device will light up at night.
