Brace yourself for a summer that might surprise you—especially if you were expecting clear skies and endless sunshine! But here's where it gets controversial: this summer could turn out quite differently from what we've seen recently, especially with the possibility of more rain before Christmas. What does that mean for your holiday plans? Let’s dive into what 1News weather expert Daniel Corbett forecasts for the first month of summer.
Summer officially kicks off tomorrow, and it’s already heating up—not just the air, but the seas around New Zealand as well. When warm ocean waters combine with changing atmospheric patterns, the result can sometimes be unexpected weather swings. Rather than a dry countdown to Christmas, many of us might find ourselves reaching for raincoats more often than flip-flops this season.
This shift is largely due to a developing weak La Niña in the Pacific Ocean, a key player in shaping our summer weather. But what exactly is La Niña, and why should you care?
La Niña is a climate phenomenon where waters in the eastern Equatorial Pacific Ocean become cooler than usual, while the western parts grow warmer. This temperature difference influences winds and pressure systems, causing stronger easterly winds along the equator from the eastern Pacific toward the northwest of Australia.
For New Zealand, this often means that the typical summer high-pressure zones push southwards over the South Island, exposing the North Island to more humid northeasterly winds. Now, here’s the part most people miss: this warmer, moist air mass sitting north and east of the country can influence how low-pressure systems behave. Sometimes, these low-pressure systems slow down or even stall over us, dumping rain over several days—not exactly what you want when imagining a sunny beach holiday.
A major factor to watch is the big high-pressure systems that tend to park themselves just east of New Zealand. These act like massive walls, slowing down weather fronts moving eastwards. When that happens, the north of New Zealand can get caught in a sticky, humid northerly flow, which increases the chances of "Tasman rainmakers." These weather events can include heavy rain and even tropical cyclones, making summer anything but predictable.
Meanwhile, the South Island might enjoy a different story. As these high-pressure systems slide east, much of the southern regions can expect more stable, warm, and dry conditions. Places like the Mackenzie Basin, Southern Lakes, and Central Otago may even see several days hitting above 30 degrees Celsius, perfect for outdoor activities.
Now, what does this mean for Christmas Day exactly? Forecasting specific weather that far ahead is tricky, but there's a pattern worth noting. If you're in the northern areas—think Hawke’s Bay, Bay of Plenty, Coromandel, Auckland, and Northland—you might want to prepare a cozy indoor backup plan in case a humid Tasman rainmaker makes an appearance on your festive day.
On the flip side, if you find yourself down in the deep south of the South Island, the odds lean more towards a day kissed by sunshine and fine weather, especially if those high-pressure systems stay nearby. Perfect conditions for backyard cricket with the family or a relaxing beach day—hopefully without the need for umbrellas or raincoats.
But here’s a question to ponder: are we becoming too reliant on these traditional seasonal patterns, and could climate shifts mean we need to rethink how we prepare for summer? Share your thoughts and predictions—will you be stocking up on rain gear, or betting on sun this year?
For a closer look at what to expect this summer as Christmas approaches, check out Dan’s detailed outlook on TVNZ+.
