Hottest November on record: NIWA climate scientists

New Zealand has just experienced its hottest November on record, according to NIWA climate scientists.

New Zealand has just experienced its hottest November on record, according to NIWA climate scientists.

Data from NIWA’s Seven-Station Series, which began in 1909, shows that last month’s temperature was 1.55ᵒC above the 30-year average. The previous record for the hottest November on record was jointly reached in 1954 and 2013 when the temperature was 1.38ᵒC above average.

This year is tracking to be the fourth warmest on record with just on a month to go. If the ranking remains the same it will sit behind 2016, 1999 and 1998 respectively.

However, principal climate scientist Dr Brett Mullan says both 2016 and 1999 experienced colder than normal Decembers, so this year may catch them up depending on the temperatures for the remainder of the year.

“This year will match 2016 (on +0.84ᵒC) for warmest-equal year if the December 2019 anomaly reaches +1.2ᵒC, which is certainly possible. It is also interesting to note that the last 10 days of November averaged +0.5ᵒC above average December temperatures,” Dr Mullan says.

The nationwide average temperature for last month was 15.3°C. The warmth was widespread, with many locations throughout the country observing record or near-record mean temperatures for November. Wairoa in the Hawke’s Bay recorded a mean maximum temperature for November of 26.2°C. This is a new record for New Zealand, exceeding the previous November record of 25.6°C (also recorded in Wairoa, in 1953). Kawerau in the Bay of Plenty recorded a mean maximum temperature of 25.3°C; New Zealand’s third-highest mean maximum temperature for November on record.

All the main centres observed well above average temperatures with Tauranga having its hottest November on record.

Unusually high temperatures hit most parts of New Zealand in the first week of November. The heat was associated with a northwesterly airflow delivering warm dry air from the interior of Australia. Kawerau reached 34.6ᵒC on November 3, 33ᵒC on November 4, and 32.1ᵒC on November 5. These three consecutive days all exceeded the previous hottest November temperature on record for Kawerau (32.0°C; recorded on November 25, 2007).

On November 23, several inland parts of the North Island observed record or near-record high temperatures. Taupo reached a high of 32.8°C, exceeding its previous November record (29.5°C recorded in 2016) by 3.3°C. Rotorua recorded a high of 30.9°C; exceeding its previous November record by a remarkable 4.3°C.

These extreme high temperatures mark the first time on record that 30°C has been exceeded in Taupo and Rotorua in November (records began in 1949 and 1964 respectively).

On 27 November, Wairoa recorded a high of 34.1°C, the equal fourth-highest November temperature on record in New Zealand.

November wasn’t just notable for its warmth. On the 10th at least 66,000 lightning strikes were recorded around New Zealand and the Tasman Sea. There was also heavy hail falls in both islands.

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