On January 29, the Nelson Mail published a prophetic story: the fire risk in the region was the highest since 2001, a year of record drought. A week later, a contractor ploughing a paddock sparked a blaze that quickly covered 2000 hectares and threatened homes.
“The start to summer was the third warmest on record for New Zealand,” says NIWA meteorologist Ben Noll. “The warm pattern has been a result of very warm sea-surface temperatures, both in New Zealand coastal waters and in the Tasman Sea, as well as a lack of cool southerly winds.”
January 2019 is now the sunniest month on record for the entire South Island. Tasman experienced a 22-day dry spell—defined as consecutive days with less than 0.1 millimetre of rain—while Nelson has recorded 84 millimetres of rain during its summer, which would normally see 224 millimetres. Regional fire officers in the region report the highest fire-danger levels they’ve seen in 20 years. Scion’s fire buildup index, which reflects the amount and dryness of fuel, is more than twice as high as the historical average.
In an average year, Nelson would have nine to 10 days of very high or extreme fire danger, says Grant Pearce, a fire scientist at Scion’s Rural Fire Research Group, but modelling shows that is likely to increase to 12-13 days on average, and 20-25 days in the worst years. It’s not the only region to experience change: “The number of severe fire-weather days is likely to increase in many parts of the country.”