Elderly folk often remark "we used to swim all year round.
Or, "we used to break ice puddles on the way to school".
Because no one is told the reasons, some think that the weather must have gone crazy and out of control due to human pollution or other silliness.
One question could be how accurate our memories are.
Do you remember what you were wearing as recently as last Wednesday? Two days ago?
Perhaps we like to recall a different time, whatever it was, as long as it differs from now. Do we selectively recall best bits?
Maybe, but to some extent the older people are recalling correctly.
When they are sure the warm summer sea has now turned colder and 15, 34 and 53 years ago there were more summery days in a row and longer frosts, it has something to do with the declination cycle of the moon.
If there was no tilt to the earth the moon would orbit us at the equator, month after month, with both earth hemispheres equidistant from the moon. But the earth is on a 23-degree lean from upright.
The moon still orbits the middle of our planet once every 29.5 days, but due to earth's tilt the northern hemisphere is slightly closer to the moon for half of every month, and during the other half of the month the southern hemisphere leans more towards it.
It means for half of each month south Australia and NZ are affected by cool airflows from the Southern Pole, in the northern hemisphere a north-facing moon draws Arctic air southwards to cool the UK, and a fortnight later their southern moon warms the Caribbean and the southern US.
We see it as the moon's arc each day getting higher or lower across our sky. Astronomers call it declination. Gardeners call it the ascending or descending moon, planting when ascending and pruning when descending.
Plus, every 18-19 years the daily arc is, during each month both higher and lower than usual in the sky, called maximum and minimum declination. Viewed from space, in a max-dec year the moon reaches 28 degrees north and south of the equator every month, in a midpoint year 23 degrees north and south, and in a minimum year 18 deg north and south.
The last max-dec year was 2005-7. Depressions, troughs and anticyclones, frosts and snowfall periods passed more quickly. Some months can be windiest on record, like October 2006.
They are quick, pouncing events and include earthquakes.
In February 2006, central New Zealand received a six-magnitude jolt and the strongest-ever Australian cyclone, Monica, brought gusts of 350 km per hour.
In March, a cyclone drenched the north of the North Island and winter floods that year affected Wairarapa, while a snowstorm affected Otago and Canterbury.
Internal stress to the earth brought earthquakes in 2007 that were within the biggest 25 ever recorded in NZ - a 6.9-magnitude shake east of the North Island in December, and a 6.7-magnitude and 6.1-magnitude in Te Anau.
Why? It's because the moon travels longer distances between latitudes in the same timeframe during max year than during min year, and angular speed increase means a faster moon brings more changeable weather.
In min-dec yrs, depressions and troughs take longer to pass over because the moon doesn't have so far to go and so goes slower. Anticyclones remain longer and in winter there are extended frosts.
In a min-dec year, the moon treks 36/37 degrees from north to south in half a month, but in max-dec year it takes 56/57 degrees in that same half-month.
In the min-dec year of 1996, the moon's daily advance northwards at the equator was 4 degrees, and by 2005 it was 6 degrees.
Around 1996/7 the moon was at min-dec, and before that; 1977-8 and 1959. In 1996-7 there were more persistent westerlies onto central New Zealand, resulting in the west and south of the South Island being wetter and cloudier and with damaging floods.
The north and east of the North Island were drier and sunnier compared to the max-dec years of 1969 and 1950-51.
So where are we now? The moon is just past mid-declination, reaching 22 degrees north and south each month. The next min-dec year will be 2015, so we can expect progressively longer summer spells in the next couple of years.
Most people live through two or three moon cycles.
It means some can recall memorable summers, for example, 1958-9, 1969-70, 1977-8, 1986, 1995-7, and 2006, and cooler summers of mid-dec years 1982-4, 1991-2, 2001-3, and 2011.
The cooler mid-dec years are some of the the El Ninos, when less heat for evaporation means less rain and some droughts. What happened in 1975-77(cooler summers) also happened in 1994-95 and repeated in 2011.
So for 2015-16, prepare for longer depressions, troughs taking longer to cross NZ, more rain and snow, and longer frosts. Anticyclones will give longer fine spells. It will be windier and drier too, like 1959.
Fifty years from now, doddery grey pensioners will remember when they were surfing and sunbathing as teenagers in 2015, and will wonder why the weather has changed.For more writing from Ken Ring, visit www.predictweather.com
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