Weather Update: September
September was another dry month for Hawke’s Bay. Rainfall across the region was below or well below normal, part of a dry pattern that covered most of the North Island, while the South Island was drenched. Temperatures sat close to average overall, though we had a taste of what’s coming late in the month when Whakatu recorded the hottest temperature in the country at 24.8°C on 27 September. We also claimed the strongest wind gust in New Zealand, with Cape Turnagain hitting 222 km/h on 10 September. Despite the lack of rain, soil moisture was still near normal at the end of the month. Sea temperatures off our coast remain cooler than usual, unlike most of the country.
The El Niño we flagged last month has done exactly what was expected. It crossed into the very strong, or “super”, category in late September and is now tracking ahead of the 1997/98 event for this time of year, with the fastest rate of ocean warming on record. It’s expected to peak in late spring or early summer and is likely to rank among the strongest El Niño events ever recorded. A positive Indian Ocean Dipole has also formed alongside it, as predicted.
For October to December, the outlook for Hawke’s Bay leans warmer and drier. Temperatures are most likely to be above average, with short warm spells brought on by strong, gusty westerlies. Rainfall is most likely to be below normal, and soil moisture and river flows are about equally likely to be below or near normal. Expect swings, too, with warm, windy days broken up by colder snaps as fronts pass through. The east of the North Island is considered particularly likely to see more frequent dry spells and faster drying of soils, so now is the time to make sure irrigation and water plans are in good shape for the months ahead.
