Weather and Hazards

The first thing to say about dealing with hazards is that the best safeguard is to go with someone else. If something happens to you they can go for help. And they might dissuade you from doing something foolish, though of course that can work the other way, and they actually persuade you to do something foolish. As with another well known activity, best to agree beforehand when ‘no’ or ‘stop’ means just that.

Secondly, tell someone what you are doing and write your name and destination in each hut book, even if you are not staying. Then people know where to start looking for you. Update your contact person regularly when you are in email or cellphone contact so they know your current location. If you are using a trail name make sure that they know what it is so they can tell the searchers that ‘Hangdog’ written in the hut books = John Smith.

And thirdly, take maps and this or another guide, and have a cellphone for checking weather forecasts. Consider a personal locator beacon and a gps (see the Gear page).

Weather Conditions

The South Island lies within the belt of winds known as the Roaring Forties that sailing ships used to hook into to speed around the southern parts of the globe. These winds pick up moisture and dump it on landmasses sitting in the middle of the ocean like New Zealand. This oceanic climate, unlike the continental climates of much of the USA and Europe, is not stable, so you need to be prepared for anything. While Otago and Canterbury have the nearest thing to a continental climate, and can be hot and dry for much of the summer (and sometimes cold at nights, especially at higher altitudes), this isn’t the case for Southland and inland Marlborough, where you can expect periods of rain even in summer. If you want to get an accurate view then there are some websites with annual climate data. Here are two I’ve set for Arthur’s Pass: Weather2, ClimaTemp. You can see that the least amount of rain is in February, but it is still only 70% less than the highest rainfall month for the year, December.

To get a weather forecast, you can go to New Zealand’s MetService website, where there are forecasts for larger centres (Invercargill, Queenstown and Wanaka are the only ones relevant for the TA South Island), but also rural forecasts for each province, and mountain forecasts covering Nelson Lakes National Park, Arthur’s Pass National Park, Canterbury High Country, and the Southern Lakes (Wakatipu to Hawea). If you are really into weather forecasting you can go to the very techy MetVuw site where there are satellite maps, radar maps, upper atmosphere readings, and forecast maps for up to ten days at regular intervals. There is also the amazing Norwegian forecasting service YR which seems as accurate as any produced in NZ. You can even type the name of a specific tramping hut into their search engine and get a forecast for that.

Another source for weather forecasts is Radio NZ, which broadcasts forecasts on the hour and have a long-range forecast at 1pm, as well as a mountain forecast at 4pm each day. Their FM frequency is 101, but you will only pick that up in population centres (Invercargill, Te Anau, Queenstown, Wanaka, Twizel, Tekapo, Nelson all have transmitters). Their AM frequencies vary over the country, but will penetrate greater distances.

And DoC visitor centres (Invercargill, Te Anau, Queenstown, Wanaka, Arthur’s Pass, St Arnaud) will have forecasts available.

Lastly, somewhat related, there is the question of daylight hours. These will change significantly over the course of walking the South Island. This chart shows that you might start out with just over 15 hours between sunrise and sunset on 1 January in the latitude of Christchurch, but three months later you are down to 11.5 hours in which to get your daily hike done – a good reason for not walking too early or late in the season. (Here’s a specific scenario: Bluff on 27 January has 15 hrs between sunrise and sunset; if you get to Picton two months later, you will experience just 12 hours.)

Hypothermia

Bad weather or a prolonged dunking in a cold river can lead to the life threatening condition known as hypothermia. The Mountain Safety Council’s pamphlet says, “Hypothermia is when the core body temperature drops to a level where normal brain and muscle function is impaired – usually at or below 35°C. When the body cannot cope it goes into survival mode, shutting down non-essential functions. Hypothermia occurs when the body cannot make up for the amount of heat lost.” The onset of hypothermia can be recognised by a person showing signs of apparent drunkenness. They might claim they are fine, but stumble, are argumentative, confused and have slurred speech. Unfortunately, these symptoms are hard to recognise in yourself if you are on your own. Treatment begins with preventing further heat loss by getting out of the wind or rain, putting on dry and warm clothes, and then giving warm sweet drinks.

Getting Lost

Assuming this is unintentional, the key thing is not to charge about in all directions and get even more lost. Better to sit down and spend some time thinking carefully. Here’s the Mountain Safety Council’s recommendations.

River Crossing

People die in NZ rivers every year. Usually from trying to cross rivers in flood. Small streams can turn into raging torrents within a day with heavy rain, but they can also drop back down again fairly quickly when it stops raining, so clearly patience might save your life in this sort of situation. There are a number of larger rivers to cross on the TA, so knowing how to do so safely is important. The Mountain Safety Council’s river safety brochure is a good guide, but you can also do training courses to gain better experience.

Read the brochure, but some basics are: make sure the key items in your pack are sealed against water in case you fall over. This will help to make it float if you are swept off your feet and have to hang on to it; plus you will want warm dry clothes after an unplanned swim in a freezing river. Shuffle your feet so they stay on the bottom and you can feel your way across. This is fairly instinctive. Use a strong stick pushed at an angle into the water on the upstream side. This is not so intuitive, but if you put it where you want to lean on it, downstream, a strong current can push it up and off the bottom, while upstream it will be pushed downwards onto the river bed. Walking poles are not going to carry much of your weight in difficult situations, hence using a stick, though they are obviously better than nothing. And lastly, if there is more than one person, each holds the other’s pack waist belt, with the strongest person upstream.

You can check the ECAN website to see relative flows over time of a number of major South Island rivers. The flow charts are not at the point you are likely to cross, but they give an idea of how high the river is compared to its lowest flows. NIWA used to have useful historical flow information but this seems to be in abeyance, and ECAN is not as good, but maybe things will return to the point where you could see a year’s worth of data in a graph, showing you whether the river is low relative to other times.

Accidents

Just as most accidents happen around the home, most accidents on the trail are not dramatic falls off high cliffs or river drownings but mundane things like tripping over a tree root and falling or twisting an ankle on a rough patch. I fell over five times when walking the South Island, and each time I was just lucky that I was able to pick myself up and continue on.

There was the time, for instance, when I was on a steep slope and stepped on some tussock. It can be very slippery stuff and in an instant I was on my back with one leg twisted up behind me. No muscles or ligaments torn or sprained, but it could easily have been like an occasion several years earlier where I tore a calf muscle from end to end simply by taking too great a step up a small bank on a casual day walk. I heard a sort of pop and felt like someone had hit me on the back of the leg with a hammer. I was barely able to hobble back to the road end and ended up out of action for weeks.

What’s the message here? That possibly the greatest hazard is simply tiredness, and with it, inattention and bad judgment. If you are going for some really long days where you will end up on autopilot, do it road walking or other easy terrain where less can go wrong.

Cars and Guns

And then there are other sorts of accidents. Road walking is always dangerous. An average of 33 pedestrians per year are killed by vehicles, and 40% of those are in non-urban areas. That is, alongside highways and back country roads. Wear bright clothing, walk on the side of on-coming traffic and never walk at night. At blind corners I often cross to the outer corner where there is more chance of being seen and a wider road margin, even though I am no longer facing the traffic. Never wear headphones of course, or you won’t hear vehicles coming.

Wearing bright clothing may help you avoid dying in the bush too. Not only will it be easier to spot if a search party is out looking for you, but there is a better chance you won’t be shot by mistake by a hunter. It does happen. There is about one accidental hunting shooting every 9 months in NZ. It is mostly other hunters who get hit and, by and large, if you are on a well established track you should be safe. Blue is said to be a good colour to wear because it is least likely to bear any resemblance to a deer compared to red, orange, brown, etc. Fluorescent orange is often worn by hunters, and can be seen a long way off,  but some say that a moving patch of orange in dense bush can act attract a hasty shot in some circumstances as much as it protects the hunter in others.

Header photo: St Arnaud Range, Nelson Lakes National Park