WHAT TO WEAR IN ICELAND
When travelling in Iceland you should bring along lightweight woollens, a sweater or cardigan, a rainproof (weatherproof) coat and sturdy walking shoes. Travellers who are camping or heading into the interior will need warm underwear and socks, rubber boots and a warm sleeping bag.
In the summer, light clothing is often all you need - but always be prepared for both cold and wet weather at all times of the year. The weather can be extremely changeable. Icelanders often say, "If you don´t like the weather, just wait 15 minutes." And always bring a bathing suit, whatever time of the year you visit.
A favourite pastime is year-round outdoor swimming in countless geothermally heated pools and lagoons, with a typical temperature of 25-28°C.
The Icelandic Meterological Office