Remembering The Great Kiwi Heatwave Of 2018
We’ve spent all winter complaining about how cold it is. But soon, we’ll be moaning about how hot it is. On those sticky and humid days that are common across New Zealand during summer, we’ll be yearning for just a little bit of the coolness we experienced in winter. But for all the heat we might encounter in the months ahead, will it be as bad as it was just a few short years ago?
Some will put it down to climate change. Others will say it was just a freak set of natural circumstances coming together to form a perfect storm of heat and humidity. Whatever it was, everyone will agree that the summer of 2017/2018 was a hot one. In fact, it was New Zealand’s hottest summer on record, and for a while, it felt like the people of Auckland were living on a Pacific island.
Meteorologists at the National Institute of Water and Atmospheric Research (NIWA) say that during one particular week from February 5, climate conditions in Auckland resembled those in Fiji or New Caledonia. The dew point, which is a measure of both humidity and temperature, failed to drop below 19 degrees for 115 hours – just short of five days. NIWA scientists likened it to the city being transported up to 10 degrees north in latitude for that period of time.
The whole country felt the heat that summer, with temperatures 2.3 degrees above average over the season. 108 places recorded their hottest summer on record, 21 their 2nd hottest and 8 their 3rd hottest. There was little respite on either island:
- On January 30, the temperature In Alexandra reached 38.7 degrees. On the same day, Clyde recorded 37.6, Middlemarch 37.4 and Cheviot 37.3.
- Wellington had 17 days above 25 degrees – their summer average is two days.
- Christchurch had respective highs of 33, 32 and 35 degrees in December, January and February 2018 with an average temperature of 23 degrees.
- Invercargill recorded three consecutive days over 30 degrees in January. It’s never done that for two days in a row, let alone three.
We have to go way back to the summer of 1934/1935 to see temperatures like that in New Zealand, but even then it was still half a degree cooler. So, what caused the great Kiwi heatwave of 2017/2018? The answer lies off-shore.
Sea temperatures around New Zealand were well above average that summer – between 2 to 4 degrees higher, with spikes in some areas of 6 to 7 degrees average. The much warmer ocean breezes, and the resulting humidity, led to a distinctly sticky feeling around the nation that summer and, particularly in Auckland, sleepless night after sleepless night. Air conditioning in Auckland had never worked harder than it did that summer, so as we look ahead to the next few months, it might pay to check that our air conditioners and heat pumps are in good working order and ready to handle the heat that is headed our way.
