Make sure you get rid of ice from your car windscreen before driving. Photo: Damian White
We’ve established that yes, Canberra is cold. But with that cold weather comes a few other phenomena that can make getting around (or into or out of) the capital a little trickier at times – fog and frost.
Canberra gets an average of about 20 or so fog days every winter, which can occasionally make landing a plane more than a little troublesome. Fog delays aren’t uncommon on cold winter mornings, but the airport has a couple of sure-fire ways to make sure you still get to your destination on time.
Early morning fog at Canberra Airport. Photo: Jay Cronan
Planes parked at Canberra Airport overnight can generally depart without a hitch – so if you need to get out of the ACT, try to be on one of those first flights (usually pre-8am). If you’re coming in to Canberra for an early appointment, fly in the night before. For more information, the Canberra Airport has a handy fog guide available on its website – or check with your airline before you fly.
While fog can make it a little harder to see on the roads (slow down and put your lights on people, it’s not rocket science), frost can make it nearly impossible to see through your windscreen – and you can cop a fine from police if you’re caught driving with view that’s frozen over.
There are many methods for defrosting a car that’s been left out in the elements overnight. Ron Bates of Bates Automotive in Mitchell has been a mechanic in Canberra for more than 40 years, and he has always de-iced his windscreen with a warm tub of water.
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He said his workshop sells plenty of ice scrapers, but he never uses them. And while it’s true the thermal shock from hot water on a frozen windscreen could, technically, crack it, he said warm water was generally OK, and that modern windscreens were built tough.
For defrosting on the inside, he said whack your air conditioner (not just the fan) on full blast on defrost – it didn’t really matter if it was hot or cold air.
As for anti-freeze in the radiator, he said if you get your car serviced regularly, chances are you already have it in there – these days almost all mechanics used a coolant that included anti-freeze properties more than sufficient for Canberra’s cold, so long as the mix was right.
“What it’s called now is anti-freeze, anti-boil, which is a coolant,” he said. “[But] if they’re going up the Snowies overnight, double check on their coolant mix.”
If in doubt, check with your mechanic.
One thing you probably don’t need to check with your mechanic is whether or not you need chains for your tyres to get around in Canberra. The short answer is no – not unless you’re planning regular trips to any of the surrounding mountains.
But that doesn’t mean you shouldn’t be aware of another admittedly rare, but potentially dangerous phenomenon that can afflict the capital’s road systems: black ice.
It sounds scary, but as Bureau of Meteorology’s Sean Carson points out, it’s not really black: it’s just ice.
“The term black ice, basically all it is is just transparent ice – it looks black because the road surface is black, which makes it hard to see. So if the road wasn’t there, it would just be clear ice,” he said.
It’s infrequent in Canberra – Mr Carson said he can’t remember the last time a warning was put out – because it requires some very specific conditions that are pretty rare.
“We get a lot of frost overnight, we get a lot of below-average temperatures, below-zero temperatures, but that doesn’t mean we’re going to get ice on the roads. You need the moisture, basically, to be on the road surface before it can freeze, and it tends to have to be a rainfall event followed by an overnight freeze, or a snow event or a melting snow event followed by an overnight freeze, both of which aren’t what I would call hugely regularly events in Canberra,” he said.
“With rain events and cloud, it is rare for it to get below zero for it to actually freeze. It can’t just be a little bit below zero, it’s got to be well below zero for quite a few hours because roads maintain a fair bit of heat too, so you’ve got to really cool the surface temperature quite a bit.”
Mr Carson said another time to be a little more wary is when there was an extra thick fog on a particularly cold morning – once again, it was rare, but if the fog was thick enough that it left a layer of water on the roads, ice could, possibly, form.
On those cold mornings, keep an eye out for traffic or police warnings – try checking canberratimes.com.au – and always drive to the conditions.