Seasonal weather in New Zealand

...how weather affects tramping in New Zealand

Weather and the seasons play a large part in the type and extent of tramping you can achieve while in New Zealand. Because we have a temperate climate directly affected by the oceans that surround us the weather patterns can change suddenly and wildly. This of course interferes with the type of trips you can undertake and when they can be done.

A wet and wild Northwesterly storm over the Canterbury Plains

I thought a quick look at the seasonal weather patterns you might experience in New Zealand might be helpful.

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

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

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 favourite 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.

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 

Temperatures rise significantly during these months and range from 20-35 degrees during the day depending on weather patterns. It is not uncommon for the night time temperature to stay above 15 degrees most nights, you will hardly need to think about a fire.   

Great weather for a tent based camping trip!

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.

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

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, 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. 

Totoranui 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 into 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 experienced 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, Arthurs 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!

How this weather affects your Te Araroa experience

There is a trekking or 'campaign' season in New Zealand for those attempting the Te Araroa trail. The time you start/finish is mostly going to be set by the existing weather and how it affects both the North Island and the South Island. It will also dictate wither you travel SOBO or NOBO.

What is the ideal time to walk the TA

What is the best time to walk Te Araroa....well, it really depends on your skill level, equipment and schedule. It usually takes from 90-120 days to walk the whole trail, about three months per island. A lot of the Trail can be walked right through the year and in fact people have walked the TA in winter but they are exceptions.

Late winter snow...on the Te Araroa Trail near Tekapo in late September...

Probably 95% of TA walkers walk the trail between October and April which is during our spring/summer/early autumn period. This is when the weather and snow conditions allow passage through the mountainous South Island. Outside of these times you will need a completely different skill set to walk the TA and your safety cannot be guaranteed.

...the same general area near Tekapo in Summer, mid January...

During Spring (October-December) the weather in the North Island is generally wet but mild. In the Southern Alps you can still expect cold, wet and snowy weather and many of the high altitude passes can be closed by deep snow and the threat of avalanches. By contrast in summer-early autumn (December to early April) the weather will gradually get warmer and clearer. By far the best and most stable weather will be from February to late March. 

Going SOBO or NOBO?

On the Te Araroa trekkers travel from the top of the North Island to the bottom of the South Island. The trail can be walked in both directions; south or north. If you travel SOBO (south bound) you start in the north and head south, if you go NOBO (north bound) you start in the south and travel north. Both are terms borrowed from the North American long trail community. SOBO dominates with 90% of TA trekkers walking south, only 10% go north.

Map: the Te Araroa Trail

TA trekkers going SOBO can start their trek in early October as they can traverse the North Island with its generally flat terrain and milder climate over Spring. This leaves the higher altitude sections of the South Island for summer and autumn. A good time to start SOBO from Cape Reinga would be early to mid October, any earlier and it is still too cold and wet. Any later and you will not finish before winter closes in on the southern part of the trail.  A SOBO will therefore be on trail from October to March.

Cape Reinga Lighthouse...northern terminus of the Te Araroa Trail!

If you are only walking the South Island (as about 25% of people do...) then a good time to start SOBO would be mid-late November or even December. The South Island is at a lower latitude than the north, it is also more mountainous so the snow stays around longer. If you attempt the SI before late November you will be facing snowed in passes, snow melt flooded rivers and a heightened avalanche risk.

Ship Cove, Queen Charlotte Trail: SOBO start of the South Island leg of Te Araroa

NOBO trekkers start in the south at Bluff and walk north to Cape Reinga at the top of the North Island. As such they are more likely to face the challenges of the mountainous South Island earlier in the season. If you are going NOBO the earliest you can safely start is late November/early December, that way you cover the South Island over summer and walk into the milder North Island over autumn. A NOBO will therefore be on trail from November to April.

The famous sign post at Bluff, southern terminus of the Te Araroa Trail

So to summarize, if you are going SOBO from Cape Reinga then plan on walking October to March. SOBO for just the South Island plan for late November to April and finally if NOBO it will be late November to May.