At this time every year, Dunedin residents start to complain about how cold it is and start asking "when is summer actually going to arrive".
Usually, weather forecasters respond by saying it is normal for this time of year in the southern coastal regions, and the hot weather will arrive in February.
But this year, MetService meteorologist John Law said weather data showed the temperatures so far had indeed been colder than usual.
The mean temperature for January at Dunedin Airport was 15.2°C.
"This year we have had a run of 12 days below the average for January.
"For the airport, the current mean temperature for January ... is 12.8°C.
"The average for the first 15 days of January 2000 was just slightly lower, with 12.4°C."
In the Dunedin city centre, temperatures were also chillier — about 2.2°C cooler than average.
"Looking at the mean temperature for January so far, it’s sitting around about 13.6°C in Dunedin.
"The average for this time of year is around 15.8°C. So it is cooler than average."
While parts of Central Otago had been sweltering in the high 20s, Mr Law said the mercury in Dunedin had only got as high as 18.8°C since January 1, and the lowest temperature was about 9.8°C, on January 8.
The temperatures at the same time last year were reaching the high 20s in Dunedin.
"So, on January 13 last year ... we got to 30.4°C.
"So it was a very different story for the start of 2024.
"It has been a fairly prolonged run of cool temperatures.
"What we’re looking for normally this time of year is a maximum temperature of around 20°C and a minimum temperature around 11°C."
St Clair Surf Lifesaving Club head guard Phoebe Aburn said she had been a lifeguard in Dunedin for the past 10 years and believed this was "one of the worst summers" she had experienced.
"The surf conditions have been stormier than usual.
"The weather conditions have been similar, maybe a little bit colder — not enough to put people off.
"We’ve still got a lot of people coming down, wanting to go swimming.
"We’re definitely used to it."
Mr Law said the cooler temperatures were caused by a slow-moving pressure pattern, which had been moving across the country for the past two to three weeks.
"High pressure out towards the west of us, and low pressure out towards the east, has brought winds through from a southerly direction.
"The patterns in the upper parts of the atmosphere are helping to keep this persistent, slow-moving setup across us.
"It’s that slow-moving nature and where those high- and low-pressure centres are sitting that is just giving us a good feed of cold southerly air, up and across New Zealand, particularly to those eastern parts of the country."
Despite the cool start, it was still early days and the second half of January looked like it would be warmer, he said.
In an online post, Niwa said a low-pressure system would form over the Tasman Sea later this month, bringing subtropical temperatures down to New Zealand, through until March.
However, it would also bring the possibility of heavy rain.
