Weird Weather: Why plants are flowering in middle of winter

Spring flowers in bloom, a delayed ski season, above average temperatures - all results of an unusually warm start to winter.
With just under a week of June remaining, figures from MetService show that Wanganui's average temperature for the month so far is 11.7C, a whole degree warmer than the June average.
Wanganui's highest temperature of the month so far is 21.1C, recorded on June 5 - two degrees above the previous high temperature record for June.
Wanganui's lowest temperature of the month so far was recorded on June 9 and was 4.1C. Some nights the temperature has not fallen below 13C.
Wanganui has not yet officially recorded a frost this year. By contrast, last winter's first frost occurred in March.
Wanganui's mild June follows on from a warm May that broke all kinds of weather records.
The average temperature for that month was 14.8C, which was 2.6C above the average, making it the warmest May since records began in the 1930s.
The top temperature for the month - 25.6C - was the highest temperature ever recorded in the city in May.
Average minimum and maximum temperatures were also considerably higher than the norm, up from the average by 2.9C and 2.4C respectively.
That was a contrast to April. The average maximum temperature for that month was 18.6C, slightly down from the normal 18.8C. The average minimum was 10.4C, also slightly down from the normal 10.6C.
The recent mild weather is starting to have an effect on nature.
Tom Carter from Springvale Garden Centre said he had heard from customers and from the nursery industry of plants flowering out of season.
"For example, there are magnolias coming into bloom now, when they're not supposed to flower until August or September.
"The unseasonally warm weather causes prolonged growth in plants and trees - and of course that will come to an abrupt end when the really cold weather finally arrives."
Mr Carter said fruit trees that blossom now run the risk of losing their young fruit to frost.
"Weather plays a very important role in fruiting. However, many of these trees may come into blossom again when spring arrives."
The mild weather has affected the ski season, with Ruapehu Alpine Lifts manager Dave Mazey, saying there was "nothing skiable" at either Turoa or Whakapapa although 6cm of snow fell on the mountain on Thursday night.
Mr Mazey said the weather had been too warm for snow-making machines to operate.
"It's the warmest May and early June that I can recall in the 25 years I have worked here."
However, Mr Mazey said the situation was not critical at this stage. "Most North Islanders don't expect to come skiing at Ruapehu until early July."
Local surfers say the sea is unusually warm for June.
Bob McDavitt from MetService said the mild weather is the result of fewer southerlies reaching New Zealand.
However, that is expected to change this weekend with cool temperatures, rain or showers, and southerly winds forecast.
"It will start feeling like winter in Wanganui this weekend," Mr McDavitt said.
Mr McDavitt said the end of June was the start of the coldest weather of the year in New Zealand. But he said the outlook for Wanganui for the rest of June and July was for lower rainfall, fewer windy days and above average temperatures than normal.
 
The numbers
11.7C: The average temperature for June so far.
4.1C: the lowest temperature this month.
25.6C: The highest temperature ever recorded in Wanganui for May.
2.6C: How much higher than the long-term norm, average temperatures were in the city for May.