More northwest winds than usual in September

Otago experienced the highs and lows of spring weather during September.

It was an unusually mild, sunny and dry September over the lower South Island, Niwa climate scientist Georgina Griffiths said.

However, a pattern of change bringing more anticyclones than normal also meant more northwest winds than usual.

An unusually cold southerly air stream hit on September 12 and 13, followed by an extremely warm two days at the end of the month, she said.

For Otago, that meant near record high and low temperatures. Alexandra recorded its highest extreme minimum of 12.9degC on September 6.

Near-record extreme minimums were also recorded on September 6 in Oamaru (13.3degC) and Ranfurly (10.9degC). Ranfurly also recorded its equal fourth-lowest extreme temperature on September 13 of -5.9degC.

Then, on September 11, low daily maximums were recorded in Ranfurly 4.2degC (third-lowest), Dunedin airport 6.1degC (third-lowest), Dunedin at Musselburgh 6.1degC (fourth-lowest) and Queenstown 3.2degC (second-lowest).

When the warmth hit on September 29, Dunedin airport recorded its equal-highest maximum 24.9degC, while Ranfurly recorded its third-highest maximum of 21.7degC. Balclutha recorded its fourth-highest maximum on September 25 with 22.7degC.

Oamaru recorded wind gusts of 80kmh on September 4, its fourth-highest for the month, and Balclutha recorded its fourth-highest sunshine hours total of 174.

Ranfurly recorded its fourth-highest extreme one-day rainfall of 24mm on September 26.

Overall, Dunedin had a warmer and sunnier month than normal, recording 168 hours of sunshine (125% of normal) and a mean temperature of 10.5degC (1degC warmer than normal).

The sunniest city was Wellington, with 189 hours, and the warmest was Tauranga, on 12.8degC.

Rainfall was about normal for Dunedin for the month, at 53mm, compared with the 64mm that fell in Wellington, 90mm in Hamilton, 68mm in Tauranga and 92mm in Auckland.

- rebecca.fox@odt.co.nz

Add a Comment

 

Advertisement