Jonathan Guildford and Matthew Littlewood16:52, May 26 2021 GEORGE EMPSON/SUPPLIED A foggy and frosty Wednesday morning in Tekapo. It has been a bitterly cold morning for many across the South Island as temperatures in several southern centres plummeted into the negatives, well below their overnight averages for autumn. According to MetService as of 7am on Wednesday, Tekapo had the lowest temperature at -8.2 degrees Celsius, Mosgiel was at -7C, Christchurch was -3C, Timaru -6C, Dunedin Airport -7.1C, Alexandra -6.8C, Invercargill -3C, Queenstown -4C and Westport was just over 3C. However, Mackenzie Country Weather NZ forecaster Jordan Langley said temperatures overnight in the Mackenzie District included -8C for Tekapo, -10C for Fairlie, and -7C for Twizel.