Sunday, 23 September 2018

The rhythm of the seasons..how weather affects tramping in New Zealand

Weather and how it influences your style of tramping

Weather is one of the major influences on when, where and how you can tramp in New Zealand. We have relatively warm oceanic weather around New Zealand, we will get warm wet air from both the South Pacific and Australia as well as an up-welling of cold air from Antarctica. 


Jon on the way back from Carrington Hut, Waimakiriri Valley, Summer 2017/2018

Added to this New Zealand is a long thin Island change, the weather at the top of the country is very different from that at the bottom. While the North Island has some mountains the main mountain range, the Southern Alps bisects the whole of the South Island. As some of these are approaching 3000 meters/9000 feet ASL they create their own weather patterns over most of the island.

Relief map of New Zealand showing mountain ranges


Lets look at the weather patterns for the country season by season and see how they influence outdoor activity.

A wild, wet Northwesterly storm builds over the Canterbury Plains


Spring: September to late November


Spring in New Zealand lasts from September to December. In the south Island Spring offers opportunities for tramping but care must be taken when planning trips. The weather in Spring can be variable but tends towards the wet, cold and windy. Mean temperatures will be around 14-18 degrees during the day, -4-5 Celsius overnight. 

Travers Valley: wet, cold and snowy conditions in the upper valley in late October...


We receive most of our rainfall for the year over these three months so any trip involving a river crossing must be carefully planned. Rivers are the biggest killer in the bush so Spring is not the time of the year for a trip that requires 30 river crossings over multiple days. 

A flooded Alfred River, Lewis Pass Scenic Reserve during a Spring rain storm...

Expect to get cold & wet when you are out tramping...thermals and wet weather gear will be your usual companion.


Spring attire in the cold...thermals, hat and wind proof jacket



Closed for business...full wet weather gear in Spring rain...nice!

That said, I have tramped in 25 degree weather in spring with nary a sign of rain so do not despair as there are fine weather windows. Spring is an excellent time of the year to visit the Abel Tasman NP as the weather is usually settled with clear, sunny days and cold frosty nights.

Spring visit to Abel Tasman National Park: sunny, fine weather all week!


During Spring a particular hazard to watch for is avalanches...large areas of the South Island are prone to avalanches and wet weather combined with late snow falls are a recipe for danger. Check for avalanche advisories in the area you are travelling to and actually pay heed to them.

 My favorite tramping destination Nelson Lakes NP is basically a no go zone in Winter/Spring due to the extreme avalanche danger. 


DOC avalanche advisory in the Travers Valley, Nelson Lakes NP

Spring is the most dangerous season for tramping so if you are going out make sure you have the equipment and skills to survive in any conditions.

Summer: December to mid March


Summer is the main tramping season in New Zealand and runs from December to mid March. This is a time of generally blue skies, light breezes and warm sunny weather. The best weather will be from February through to March as early Summer can still be wet and cold.

Summer daytrip to the Otira Valley, Arthur's Pass NP


If you are really lucky you will get to experience a classic Canterbury Nor'wester...near gale force winds combined with 30+ temperatures. Its just like being in a fan forced oven....lovely!

Classic Summer tramping in the Henry Valley, St James Conservation Area: hot, sunny, no wind and endless blue skies 

On the Lewis Pass Tops, Boxing Day 2015
You can and will get wet, windy and cold weather due to our oceanic climate but it is much rarer in Summer. You will often have extended periods of hot sunny weather: blue skies predominate. Great weather for a tent based tramping trip!

Summer is the time for those camping trips

Unfortunately Summer is also the busiest period as everyone else is out seeking the warm weather so expect company at points of interest and in the huts. 

In summer expect company in that DOC back-country hut...

Summer is great for tramping as you can basically wear a t-shirt and shorts for most of the time and in late summer it is even possible to swim in rivers, lakes and the ocean. I went for a swim in Lake Rotoroa near Sabine Hut in February of this year and it was absolutely beautiful.

Lake Rotoroa, Nelson Lakes National Park


Summer is also the season to go on those tramps up river valleys...water levels will be low enabling better access.

In the Upper Waimakiriri River Valley in the height of Summer


Make sure you have sunscreen and a wide hat as the sun can be hellish in New Zealand. 

Summer tramping attire: shorts, t-shirt, gaiters and hat

Watch for summer tramping hazards: sun burn, sun stroke, dehydration, hay fever. 


Autumn: late March to early May

Autumn is actually my favourite time of the year to go tramping. The weather will still be fine in the first month or so and the huts are a lot less busy as the tourists and occasional good weather trampers tend to stay away. Many is the autumn tramp where I have found myself alone in a 12-20 bunk hut...it is total bliss after the frenzy of summer crowds. 

Jon in his very own 6 bunk hut...three days in Magdalen Hut in May 2017


The weather patterns in autumn tend to be the most stable of the year, you will often get 4-7 day periods of fine weather inter-spaced with 2-3 days of rain so it is a bit easier to forward plan a trip.

Beautiful sunny weather mid May in the Boyle River Valley


In late autumn you will start to encounter winter and in New Zealand winter can be savage. You will get night time frosts and they can be chilling. We often receive our heaviest snow falls in late autumn so watch for south-westerly storm fronts coming in from the Antarctic region. Mean temperature over Autumn is 7-21 during the day but it can drop to -5 on a night with a heavy frost.

Heavy frost in the Boyle River Valley, May 2017


Autumn is an excellent time of the year to visit coastal walks like the Abel Tasman Coast Track or Queen Charlotte Track, you can't swim but the huts are a lot quieter. In fact the Abel Tasman is one of the few year round tramping locations in New Zealand as the transport options and mild climate enable trips even in the depth of winter. 

On the Queen Charlotte Track in early Autumn 2016


Totaranui Beach, Abel Tasman NP...still beautiful even in early Autumn

A handy tip for Autumn and Winter tramps: if your water comes from a rainwater tank draw sufficient supplies to last for breakfast and day time drinking before it gets dark. The taps freeze overnight (if there is a frost) and you wont be able to get any water out of the tank for the morning coffee.

Experience...

Winter: May to early September

As far as tramping goes winter can be the quietest of the outdoor seasons.  

Bealey Spur Hut, Arthur's Pass in Summer...

...and Bealey Spur Hut in Winter

New Zealand has a temperate climate which means we generally have fairly even weather patterns but we are surrounded by oceans and close to Antarctica. This means we can get sudden and savage storms rolling up from Antarctica. Snow fall can be heavy, it is not uncommon for 1-5 metres of snow to fall in a winter storm.

Heavy snow at Lewis Pass in early September 2017


Mean daily temperatures range from 1-15 degrees but frosts of -10 are not uncommon further south. When you factor in wind chill you are talking about -20/-25 in high altitude places like the Lewis Pass & Nelson Lakes tops, the Tararua's and alpine regions of Fiordland. For example, last year Lake Angelus Hut in Nelson Lakes (at 1800 metres) had -20 degree temperatures every single day for two weeks because of wind chill. That is some serious cold weather!


Lake Rotoiti, Nelson Lakes NP in winter snow


Over winter only very experienced trampers should be adventuring in most of the back-country...the risks from hypothermia, frost bite, avalanche and sudden storm are too great.  People do go out but they are usually climbers or hardier souls. Any tramping that is done will tend to be confined to the valley floors, close to a road end or in regions less affected by snow and cold like Golden Bay and the far north of the North Island.

Late Winter tramping in the Hawdon Valley, Arthur's Pass National Park

Winter has its own requirements when it comes to equipment; more and warmer clothing of course but also specialised gear like skis, snow shoes, ice axes, crampons, avalanche beacons and four season tents. All of these pieces of gear need training so that is why it is a good idea for the winter tramper to do a basic snow skills course to learn how to use it all correctly.


Winter ice tools: An ice axe and crampons provide traction on snow and ice


Personally, during winter I tend to stay closer to home, if I am tramping it will be on the Port Hills/Banks Peninsula, the Canterbury plains or in places like the Abel Tasman NP. Most of the Southern Alps are out of bounds, even the eastern foothills can be dangerous as they are often covered in snow. 


Snow on the Southern Alps from the Port Hills, Christchurch


A closer view of the snowy Southern Alps from atop Mt Oxford, Canterbury


I have gone on overnight winter trips before but I usually confine my activity to fitness walking and day trips. One of my winter tasks is crossing off sections of the Christchurch 360 Trail around the city. I have been section walking it for a couple of years and only have three sections left to complete.

Urban walking on the Christchurch 360 Trail (Mt Pleasant to Sumner) on a beautiful mid winters day

Another option is a trip to Quail Island on a warmer winter day...

Quail Island, in Lyttleton Harbour is a great winter time walking location

If you live in snowy Canterbury and are really Jones-ing for a night in a hut why don't you tramp up to Packhorse Hut or Rod Donald Hut both on the Te Ara Pataka/Summit Walkway. Both huts are wonderful places to stay and are on the hut booking systems so you can guarantee a bed for the night.

Rod Donald Hut on Banks Peninsula is a great location for a winter overnighter...
...as is Packhorse Hut!



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