Embedded in the main band of rain, severe thunderstorms developed in the unstable air over the Auckland region. But, as the climate continues to warm, the amount of water vapour in the air increases. I am confident climate change contributed significantly to the incredible volume of rain that fell so quickly in Auckland this time. One degree of warming in the air translates, on average, to about 7 percent more water vapour in that air. The globe and New Zealand have experienced a bit over a degree of warming in the past century, and we have measured the increasing water vapour content.

Source: Stuff January 28, 2023 22:55 UTC