It has been a month of umbrellas rather than sunscreen across much of New Zealand, with persistent rain, low sunshine and deadly storms dominating headlines and daily life.

For many people, it has felt like midsummer never really arrived. Is it simply bad luck, or is there something more going on?

As with most aspects of our climate and weather, the answer isn’t straightforward. It reflects the interplay between New Zealand’s geography, warmer-than-average ocean temperatures, large-scale regional climate patterns and long-term global warming.

Climate observations back up what many New Zealanders have been feeling this month. Across northern regions in particular, sunshine hours have been well below average, while rainfall totals have been far above normal.

In central Auckland, a weather station in Albert Park had recorded around 244mm by January 27 – nearly three times the (1981–2010) average for the month. At Mount Maunganui, the month-to-date total had climbed to roughly 385mm, more than four times the norm.

Similar patterns have been seen in many parts of the upper North Island, with repeated heavy rain events, high humidity and prolonged cloudy spells. The result has often been soggy soils, swollen rivers and increased risks of flooding and landslides.

While each storm........

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