The road had disappeared. It was there a second ago, winding up the snowy mountain pass, but suddenly I couldn't see it any more: only whiteness. I slowed to a crawl, squinting for the next road marker to prevent me driving off the mountain. We didn't dare stop – any car behind wouldn't see us until they'd crashed into us – so we edged on, the occasional vehicle only looming out of the murk as it passed us. Then, just as abruptly, we emerged from the white-out, the reassuring sight of Route 1 meandering into the valley below.
None of this was surprising. After several days driving in Iceland, we knew that Route 1 – the 1,300km road that circles the island – could throw anything at us, and all our little Hyundai i20 could do was cling to the Tarmac (or gravel, in some sections of the road) and let the capricious Icelandic weather have its wicked way.
My boyfriend and I were on a week-long anti-clockwise tour of Route 1, eager to see the icy north, with its promise of volcanoes and bubbling mud pools. There are more accessible craters – Thrihnukagigur is just 13km from Reykjavik – and the much-visited Golden Circle provides a handily located snapshot of Iceland's tempestuous landscape. But with the majority of the country's 320,000 inhabitants (not to mention its tourists) in the Reykjavik area, we wanted to see how the rest of the country braves an Icelandic winter.
The short answer is: with a four-wheel drive and a shovel. We had neither, and as we began our trip by driving south from Reykjavik it quickly became clear what we were up against. Iceland sits just below the Arctic Circle astride the ever-growing gap between the North American and Eurasian tectonic plates. It is is a landscape in motion: one of voluminous waterfalls, brooding volcanoes, fields of lava, boulders and churning seas crashing onto black-sand beaches. We saw all this in a morning, stopping to admire the heavy veil of the Skogafoss waterfall, just south of the Eyjafjallajokull volcano that clogged the airways with its ash cloud in 2010. Then we stretched our legs on the beach at Vik, our footprints exposing the black sand beneath a topcoat of snowflakes. The weather changed constantly: the morning sun was eclipsed by cloud, snow and gales, before reappearing as a fierce slash of yellow, silhouetting the jagged rocks on the coastline.
There were few other tourists. We chatted with a lone traveller at Vik, still reeling from seeing the Northern Lights the night before, and encountered just one other couple at our first night's stop, a guesthouse east of Skaftafell, the blueish toe of the massive Vatnajokull icecap. Like us, they'd driven from Reykjavik, but were turning back after a day's exploration. We breakfasted together in semi-darkness – in winter the sun doesn't rise until at least 9.30am – before they saw us off with good-luck wishes and a recommendation for a website that monitors road conditions.
It felt slightly foolhardy, setting out in ferocious winds and rain, but it was exhilarating, too, even though the weather quashed our planned boat trip on the Jokulsarlon glacier lagoon. Here, trapped in a pocket of water just inland, bobbed boulders of ice broken free from the icecap. We bundled up to gape at these frozen sculptures, tinged blue and threaded through with grey like varicose veins.
The wind kept up a howl all day; it buffeted us along as we followed Route 1 round the eastern fjords, long fingers that emerged ghost-like from the cloud. We picnicked in the car near a fishing village, watching the spray lash against the shore. As the road headed inland, it turned perilously slippery, a blizzard threatened and with it, nerves rose. We'd been aiming to get to Lake Myvatn that night, but with dusk descending, we called it a day in the small town of Egilsstadir.
Over a pint of Gull (Icelandic lager) I doubted the wisdom of our expedition. Might not the Golden Circle have been a wiser choice in winter? But when darkness lifted the next morning, my doubts dissolved. The wind had died and a bright, low sun cast a luminosity over the snowy road north-west to Lake Myvatn. We drove calmly through vast fields of white punctuated by the outline of volcanoes, revelling in the clear light that reminded us we were at the top of the world.
We'd been told Lake Myvatn was beautiful, but nothing prepared us for how other-worldly it was: steam hissed from the ground in eggy plumes (this sulphuric belching makes the whole country smell), a geothermal river snaked through snow like a hot knife through butter, and lunar shapes protruded from the lake. We lingered here in sunshine for two days, climbing the huge Hverfjall crater and exploring the slopes around the Krafla volcano, where a power plant harnesses the area's geothermal energy for hot water and electricity.
At night we combated the -11C cold by relaxing in the Myvatn Nature Baths, north Iceland's version of the Blue Lagoon; unlike in its touristy counterpart, we shared the 40C thermal waters with just a few locals. Then, as though in recompense for its prior temper tantrums, the weather awarded us winter's top prize: the Aurora Borealis, hanging like a brushstroke of incandescent green over our cabin.
We left, reluctantly, following orange skies west to Akureyri, the capital of the north, before travelling south through that white-out towards Reykjavik. In the end, we spent our final day visiting the Golden Circle. It was easy to see why the ethereal Thingvellir National Park inspired early Icelanders to choose it as the site of the country's first parliament, but we encountered the first tour buses of our trip there.
At Geysir, we joined a clutch of Brits to gawp at the bubbling pools, which farted water 20m high every 10 minutes; while at Gullfoss we slid down the icy path to take close-ups of this mighty waterfall. But our photos were the same as everyone else's. I couldn't help but feel smug that we'd already seen so much more.
The writer flew with Icelandair (0844 811 1190; icelandair.co.uk) which offers returns from Gatwick, Heathrow and Manchester to Keflavik airport. Alternatives include easyJet (0843 104 5000; easyJet.com) from Luton and Manchester and WOW Air (00 354 590 3000; wowice land.co.uk) from Gatwick.
Guesthouse Hali, Sudursveit (00 354 478 1073; hali.is). Doubles start at ISK14,000 (£70), including breakfast. Dimmuborgir Guesthouse, Lake Myvatn (00 354 464 4210; dimmuborgir.is). Doubles start at ISK12,500 (£62), room only.
Visit Iceland (00 354 511 4000; visiticeland.com).