Endless summer - or an endless wait for sun

Picture / Carolyn Elliott

In Auckland on January 2, the Herald wondered when it was all going to end, looking back on a wet Christmas and a year which had delivered "tropical storms accompanied by a wearisome procession of northeast gales, with fireballs, tornadoes and other freaks of the weather" - and an incredible 2808mm of rain, more than two-and-a-half times the annual average.

By the end of the month, the sunshine had shut out the dross of 1956. It rained on just one day in Auckland and the hours of bright sunshine hit 310 - an average of 10 hours a day, every day. On January 14, the city's weather station recorded 13.9 hours of bright sunshine, about 30 minutes shy of the theoretical maximum.
In Tauranga, where the protection of the Kaimai Ranges always breeds a warm expectation, it was even better - 313 hours of sunshine for the month. So was this our greatest summer? Probably not. But, for the most part, it was a bloody good one.

But we shouldn't get too dewy-eyed about the good old days. While we may fondly recall that terrific three weeks of unbroken January sunshine, our fading memories allow us to gloss over the fact that December was a shocker and that it really turned to custard in February when we were all back at work or school.

Perhaps some dwell on those carefree days as we grow older because we realise we're running out of time and opportunity.

The theory that our most vivid memories are formed in the two decades after turning 10 seems to have some legs. For the baby-boomers and beyond, it's gratifying to believe the lifestyle was so much better then - back to January 1957, say, when six surfcasters landed 147 big snapper in a day's fishing off rocks in the Kaipara Harbour, as the Herald reported.

But how do the figures really stack up - what is the truth? To find the answer, we pulled together a barrage of statistics from Niwa, covering 50 years of sunshine hours, rainfall, days when rain fell, and temperatures for Whangarei, Auckland and Tauranga. Some of the testing stations changed over that period and there are gaps in the data, but the idea was to get an overall impression rather than present an unshakeable set of statistics.

The result: three months of sunshine with warm temperatures and just a few drops of rain are as foreign to us as socks with sandals. In the past 50 years there has not been a summer - December to February - in the upper North Island - that you'd want to write a book about.

What makes a great summer weather-wise? It seems a simple enough question, but there's a world between one person's holiday ideal of a hammock under cloudy skies and another's of a towel on the sand beneath scorching sun.

Warm but not too hot? Enough cloud to allow the sunburn to heal? A splash of rain to keep the tomatoes prospering?

For this exercise, we're on holiday for a long time at the beach, lake or river and we're after sunshine, warm temperatures and no rain through the full three months. A ban on wind stronger than 10km/h would be nice, but those statistics aren't available.

In the upper half of the North Island we always get the rough with the smooth.

If we were relying on straight statistics we'd head for Central Otago, where rain keeps well away and days are long and hot. But who wants to stare at tussock all summer long?

Hawke's Bay and Gisborne are more appealing and the odds of sunburn outside a dry tent are as good there as anywhere.

However, our eyes are on Auckland and its two favourite playgrounds, Northland and the Bay of Plenty.

To start, a bit of what we know from the Herald's daily weather chart - a tale of three cities written over the last century:

* Whangarei is wettest (mean annual rainfall of 1410mm) and has less sunshine than its sister centres (1925 hours a year). Its "winterless north" label apparently hangs on its relative warmth.

* Believe it or not, Auckland is the driest (1103mm) and sits in the middle on sunshine hours (2067 hours).

* Tauranga is one of the sunniest spots in the country (2258 hours, giving it the equivalent of an extra full month of constant sunshine over Whangarei), but when it rains it tends to pour (1207mm).

Now for what we didn't know - whether those summers then were as good as we thought.

The quick answer is no, they weren't, and you're just as likely to get a good summer today as you were in 1950 or 1960.

Pulling the key indicator of sunshine hours from Niwa's data shows that the summer of 1956-57 wasn't bad, one of six standout seasons spread over the past 50 years. Interestingly, every decade has produced at least one super-summer: 1956-57, 1969-70, 1973-74, 1986-87, 1990-91, 1997-98.

Scientists might frown at the extrapolation, but the statistics suggest we can expect a really great summer in northeastern New Zealand every eight years on average. The signs are that this summer will be quite reasonable - perhaps warming us up for a beauty in 2005-06. Or the next year.

The graphics show that four of our super-summers had a particular claim to fame:

* 1956-57: most sunshine hours (average of 743 hours over the three centres for the three summer months).

* 1973-74: fewest rain days (average of 13.6 days).

* 1986-87: driest (average of 148.7mm across the three cities).

* 1997-98: warmest (mean daily maximum temperature of 24.8 degrees).

There are pitfalls in averaging summer statistics for three coastal cities so far apart - stretching about 300km from Whangarei to Tauranga - then declaring an average result across a broad region.

Super-summer or not, if you pitched your tent in the wrong place at the wrong time, you could have had a ghastly holiday.

It may not have rained in Whangarei in January 1957, for example, but 10 days in February were wet, and sunshine hours were half those of the previous month.

Statistically, the brilliant January and a pretty good December eroded the influence of a suspect February, and 1956-57 goes down - in Northland, Auckland and the Bay of Plenty - as a summer to write home about.

In 1990-91, things were as good as they get in sunshine hours for Whangarei and Tauranga.

But in Auckland it was just a bit above average - 134 hours below the city's 1973-74 best (the equivalent of an extra five full days of sunshine for each of the three summer months).

And while it rained on just 12 days in Tauranga during the summer of 1986-87, Auckland put up with 22 rain days, and Whangarei recorded 20.

Where the sun shines most

If sun matters to you most, 50 years of statistics show that Tauranga (or probably anywhere from Ohope to Tairua ) offered the best chance of gratification.

In all but one of the six super-summers, the Bay city took the top spot for most hours of bright sunshine, including a staggering 819 hours in 1990-91 and 808 hours in 1986-87. Over the three months of summer, that's an average of a little over nine hours a day for those years.

Right through the 50 years, Tauranga has been consistent, averaging 689 hours total for the three summer months (compared with 590 hours for Whangarei and 630 for Auckland), including a magical six consecutive years from 1994-95 when the average was 748 hours.

In the super-summers, Auckland bathed in most sunshine in 1973-74, when it recorded a total of 768 hours (an average of 8.5 hours a day through December, January and February). Whangarei has always brought up the tail, except in 1990-91 when Auckland slipped away.

For those who like it hot

The statistics are pretty clear about the warmest of the centres.

Whangarei sneaks ahead of Tauranga and Auckland is usually several points behind the pack, although the position of the reading stations may influence those ratings slightly.

In 1997-98, Whangarei had the lowest sunshine-hours total for the six super-summers (more than 220 hours below the Tauranga record), but the mercury there that summer ran at a mean daily maximum average of 25.6 degrees.

That's been our most sizzling summer (throughout the world in 1998 temperatures reached record highs), with Tauranga notching up 24.7 degrees and Auckland not far behind.

If you took a late holiday in Auckland that year, you had every right to imagine it could hardly get better.

For 10 consecutive days over late January and early February the daily maximum hit 30 degrees in the city.

Good times, dry times

If sunshine hours and warmth are key ingredients for a terrific holiday season, a dry bit of beach to stick your towel on can't be far behind.

You can never be sure of avoiding rain in this part of the country, but each of the three cities had their moments.

Tauranga enjoyed the driest summer of the past 50 years, with just 90.2mm of rain spread over 17 days, in the three months of 1953-54. It followed that in 1986-87 with 96.9mm on just 12 summer days.

Aucklanders probably couldn't believe their good fortune in 1973-74 when rain fell on just 11 of the 90 summer days, spilling a miserly 96.9mm over the city. Whangarei enjoyed similar parched times in 1953-54, with its lowest summer rainfall of 101.7mm.

When the rain comes down

All three cities were close statistically on the number of rain days and actual rainfall when averaged through the six super-summers. But cast the net over the full 50 years and it suggests you have a better chance of waking up to a leaky tent in Whangarei.

Whangarei takes six spots on the top-10 list of the wettest summers, but the record goes to Tauranga, where in 1988-89 it bucketed down - 598.6mm of it, almost half the average annual rainfall, leaving just 55 days without rain in those three months.

Tauranga holds another rainfall record - most rainfall in a summer month.

If you took December off in 1962 and headed for the western Bay of Plenty, your picture album must be full of umbrellas, gumboots and long faces. In that month, an extraordinary 446.5mm washed over the city (only 96mm in Auckland). It's the wettest summer month on record.

If you're staying at Mt Maunganui now and some bloke in the next bach tries to tell you that they don't make summers like they used to, you could ask him a few simple questions. Were we winning at cricket ? Were the tuatua thick off the main beach? Was his favourite band playing every night?

Were the girls showing as much interest in him as he was in them? Was he drinking a bit then? Did he win the Golden Kiwi?

When the good times roll with the thunder, the thunder may not seem quite so bad.