Niwa National Climate Centre climate scientist Gregor Macara said the Musselburgh weather station recorded a temperature of 28.7°C, between 1pm and 2pm this afternoon.
"That’s amazing — very impressive."
The previous record was 28.5°C, which was recorded on April 4, 2021.
The records began in 1947, and the only other time the mercury neared this level was on April 8, 1955, when it hit 26.6°C.
Unofficial MetService temperatures showed the temperature in other parts of the city reached more than 30°C.
Mr Macara said much of the Otago and Southland region was experiencing hot temperatures, caused by strong northerly foehn winds.
Foehn winds occur when an air mass hits the Southern Alps, dries out as it travels over the mountains, and then warms up again as it travels down the other side.
The temperature is expected to slowly decrease now, and a few late afternoon showers were possible as fresh southwesterlies develop.
